<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2025 Workiva-->
<!--r:c2e76963-9af4-48cf-b61a-8b2e6fa509b9,g:22d3b42a-f65a-4b76-a718-a806e7a23fad-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://westwoodgroup.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="simple" xlink:href="whg-20250630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOMELOSS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_47bc1a5a-5bdb-4bb0-a34c-7c7eb01c4251" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_StatementTable_47bc1a5a-5bdb-4bb0-a34c-7c7eb01c4251" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_be687bd5-66cd-468b-aecb-207aa637b84d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_47bc1a5a-5bdb-4bb0-a34c-7c7eb01c4251" xlink:to="loc_srt_ProductOrServiceAxis_be687bd5-66cd-468b-aecb-207aa637b84d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_be687bd5-66cd-468b-aecb-207aa637b84d_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_be687bd5-66cd-468b-aecb-207aa637b84d" xlink:to="loc_srt_ProductsAndServicesDomain_be687bd5-66cd-468b-aecb-207aa637b84d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_be687bd5-66cd-468b-aecb-207aa637b84d" xlink:to="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_873a2ec3-c7ab-4112-ada6-7d7e7a72eec0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetManagement1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:to="loc_us-gaap_AssetManagement1Member_873a2ec3-c7ab-4112-ada6-7d7e7a72eec0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentPerformanceMember_373a3beb-2df5-4185-ba75-cdf550279295" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentPerformanceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:to="loc_us-gaap_InvestmentPerformanceMember_373a3beb-2df5-4185-ba75-cdf550279295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiduciaryAndTrustMember_b4b75263-d2c4-4f89-8718-4235ee0b3233" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FiduciaryAndTrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:to="loc_us-gaap_FiduciaryAndTrustMember_b4b75263-d2c4-4f89-8718-4235ee0b3233" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedFeesMember_942f7fa4-b9e8-4cb8-894f-e3b0193bc12b" xlink:href="whg-20250630.xsd#whg_TrustPerformanceBasedFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_a8f8d0f0-fcaa-4fb7-b38a-e34c6fc4cabe" xlink:to="loc_whg_TrustPerformanceBasedFeesMember_942f7fa4-b9e8-4cb8-894f-e3b0193bc12b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_47bc1a5a-5bdb-4bb0-a34c-7c7eb01c4251" xlink:to="loc_srt_StatementScenarioAxis_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87" xlink:to="loc_srt_ScenarioUnspecifiedDomain_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_78b515f1-48fe-4957-a5b4-1f2e7103af7f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_fcc069b0-2ca7-4dfe-b3b0-6dee25898d87" xlink:to="loc_srt_ScenarioUnspecifiedDomain_78b515f1-48fe-4957-a5b4-1f2e7103af7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_44c83988-c633-4405-aa32-eafe7f4ea7e9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_44c83988-c633-4405-aa32-eafe7f4ea7e9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_56ec1e67-7629-47e5-9d22-6095b612c0be" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillImpairmentLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_56ec1e67-7629-47e5-9d22-6095b612c0be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_638491c8-6a67-4fcd-aa71-35b1db7345aa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_638491c8-6a67-4fcd-aa71-35b1db7345aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_a034c012-3a3e-4790-8e37-106c563dda79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_a034c012-3a3e-4790-8e37-106c563dda79" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_a5569ea6-ce69-4053-b566-89d4c2422c37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_a5569ea6-ce69-4053-b566-89d4c2422c37" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_ccb994e5-508a-4db5-b85f-0a93bcfed597" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_ccb994e5-508a-4db5-b85f-0a93bcfed597" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_d00a55e9-8a72-4aef-8819-b52379750027" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_GainLossOnInvestments_d00a55e9-8a72-4aef-8819-b52379750027" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestInNetIncomeLossOtherNoncontrollingInterestsNonredeemable_4f6c882c-b7fc-4b98-ae6c-587614e11f82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestInNetIncomeLossOtherNoncontrollingInterestsNonredeemable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_NoncontrollingInterestInNetIncomeLossOtherNoncontrollingInterestsNonredeemable_4f6c882c-b7fc-4b98-ae6c-587614e11f82" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_0bc5ad57-03b6-44e6-bc6f-eba7a98e2fe4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_0bc5ad57-03b6-44e6-bc6f-eba7a98e2fe4" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_83a7a428-ff26-4fff-a776-c8d55022befc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ComprehensiveIncomeNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_83a7a428-ff26-4fff-a776-c8d55022befc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_93306cda-6945-4e04-b3e1-2bff0907bbae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_b01a0b91-f4fd-468b-a987-873523633594" xlink:to="loc_us-gaap_ProfitLoss_93306cda-6945-4e04-b3e1-2bff0907bbae" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="whg-20250630.xsd#CONDENSEDCONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_0f372582-1903-477e-9fa3-2918f14b8ffe" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_StatementTable_0f372582-1903-477e-9fa3-2918f14b8ffe" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_79bc8bd6-1189-4f24-8097-7ee157221606" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_0f372582-1903-477e-9fa3-2918f14b8ffe" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_79bc8bd6-1189-4f24-8097-7ee157221606" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_79bc8bd6-1189-4f24-8097-7ee157221606_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_79bc8bd6-1189-4f24-8097-7ee157221606" xlink:to="loc_us-gaap_EquityComponentDomain_79bc8bd6-1189-4f24-8097-7ee157221606_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_79bc8bd6-1189-4f24-8097-7ee157221606" xlink:to="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_fecc808d-6e6d-403d-8b23-4f0587364b37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_CommonStockMember_fecc808d-6e6d-403d-8b23-4f0587364b37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_e244807d-f6b0-412f-a2ce-adae230bea1b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_e244807d-f6b0-412f-a2ce-adae230bea1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_b9299a29-d9b1-4d38-accd-1077fd42c22a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_TreasuryStockMember_b9299a29-d9b1-4d38-accd-1077fd42c22a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_1f36b2d4-6cb7-46c1-b3f2-2e8b905f835b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_1f36b2d4-6cb7-46c1-b3f2-2e8b905f835b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_ed12d604-66a8-4f8c-8028-3ea7c3cb4c15" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_RetainedEarningsMember_ed12d604-66a8-4f8c-8028-3ea7c3cb4c15" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_36d0af08-14e2-432e-888c-8b1f61b69fd2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_205f68e7-ad88-4a0b-b475-4e5ebe8685d4" xlink:to="loc_us-gaap_NoncontrollingInterestMember_36d0af08-14e2-432e-888c-8b1f61b69fd2" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_eeeb1be7-63e7-4a5f-a5ac-ba049fd1b7d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_StockholdersEquity_eeeb1be7-63e7-4a5f-a5ac-ba049fd1b7d8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_5ce74b21-4e1f-44cb-8381-4d9b9c0abd5c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_5ce74b21-4e1f-44cb-8381-4d9b9c0abd5c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_4b4e5383-be74-4c18-be83-2141cd4447a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_NetIncomeLoss_4b4e5383-be74-4c18-be83-2141cd4447a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_266a6cb8-48e4-45fa-abcb-d6c26d7696ac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_266a6cb8-48e4-45fa-abcb-d6c26d7696ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_23b806d5-52e4-49bc-8f0c-4528441a4e04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_23b806d5-52e4-49bc-8f0c-4528441a4e04" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_14985e9f-9301-42a7-805a-77fc7cc2152d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_14985e9f-9301-42a7-805a-77fc7cc2152d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_21bbbb74-6491-4efa-98a8-cd09b2aa0be8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_21bbbb74-6491-4efa-98a8-cd09b2aa0be8" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_1039cb45-f91f-4e30-b63e-752f03d594cf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_DividendsCommonStock_1039cb45-f91f-4e30-b63e-752f03d594cf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_2adf12b0-471b-4610-9c76-c531569ec694" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_2adf12b0-471b-4610-9c76-c531569ec694" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockAwardForfeituresDividends_da2c8c65-dc69-4399-92e4-d1bd0c565019" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockAwardForfeituresDividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_RestrictedStockAwardForfeituresDividends_da2c8c65-dc69-4399-92e4-d1bd0c565019" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_11c52b22-c75f-466c-bd2e-94f9c4c528bd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_11c52b22-c75f-466c-bd2e-94f9c4c528bd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_a8341fbc-cafd-4c8d-98ee-90b8f2c98364" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_a8341fbc-cafd-4c8d-98ee-90b8f2c98364" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TreasuryStockSharesAcquiredEmployeeStockPlan_190a6028-9e5d-400a-ab6b-00cd270c485c" xlink:href="whg-20250630.xsd#whg_TreasuryStockSharesAcquiredEmployeeStockPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_whg_TreasuryStockSharesAcquiredEmployeeStockPlan_190a6028-9e5d-400a-ab6b-00cd270c485c" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_7bdf3157-2f1b-48e5-807c-c744b20bd26a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_7bdf3157-2f1b-48e5-807c-c744b20bd26a" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_60a2f777-c347-4913-afbb-c43e2a72a25d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_47180a76-48d5-4267-a586-acce2227640b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_3558af98-c488-478d-a830-ed717062277b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_ProfitLoss_3558af98-c488-478d-a830-ed717062277b" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_642660e5-d964-4239-850b-584fab2dfb75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_642660e5-d964-4239-850b-584fab2dfb75" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_1b6ef102-92f7-45ce-81b8-46f1cc8dbd83" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_1b6ef102-92f7-45ce-81b8-46f1cc8dbd83" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_8fcbd9f9-5f8f-4895-bbd9-669312cc31b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_8fcbd9f9-5f8f-4895-bbd9-669312cc31b4" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2060b27d-d7a5-417b-93f8-1b2ac8766590" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2060b27d-d7a5-417b-93f8-1b2ac8766590" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_560ce953-30be-48ce-86a8-b10ca21e8ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_560ce953-30be-48ce-86a8-b10ca21e8ea4" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ReturnOfCapital_f138c413-2b64-4776-a057-87c8b06044ae" xlink:href="whg-20250630.xsd#whg_ReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_whg_ReturnOfCapital_f138c413-2b64-4776-a057-87c8b06044ae" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_3944f7b0-4149-441e-8b45-8f0b3d8a15e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_3944f7b0-4149-441e-8b45-8f0b3d8a15e0" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan_e1e4b6f4-fdff-422a-81bf-30fadb7461f3" xlink:href="whg-20250630.xsd#whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_45a32648-235d-4e20-af13-bbf1801297ef" xlink:to="loc_whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan_e1e4b6f4-fdff-422a-81bf-30fadb7461f3" xlink:type="arc" order="24"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SUBSEQUENTEVENTS" xlink:type="simple" xlink:href="whg-20250630.xsd#SUBSEQUENTEVENTS"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/SUBSEQUENTEVENTS" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_e71c8214-05aa-4113-b0d7-62bff8fc7e82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_671fd41a-e3bb-47b1-a366-f17541b0b009" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_e71c8214-05aa-4113-b0d7-62bff8fc7e82" xlink:to="loc_us-gaap_SubsequentEventTable_671fd41a-e3bb-47b1-a366-f17541b0b009" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_a17f8f54-bc20-40a0-a442-4d7e8432732a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_671fd41a-e3bb-47b1-a366-f17541b0b009" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_a17f8f54-bc20-40a0-a442-4d7e8432732a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_a17f8f54-bc20-40a0-a442-4d7e8432732a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a17f8f54-bc20-40a0-a442-4d7e8432732a" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_a17f8f54-bc20-40a0-a442-4d7e8432732a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_dd7cc61c-e335-4df2-b6c7-50f046b501a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a17f8f54-bc20-40a0-a442-4d7e8432732a" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_dd7cc61c-e335-4df2-b6c7-50f046b501a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_d96a21be-bd67-4f31-8f3f-3c838696ddf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_dd7cc61c-e335-4df2-b6c7-50f046b501a3" xlink:to="loc_us-gaap_SubsequentEventMember_d96a21be-bd67-4f31-8f3f-3c838696ddf6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONTables" xlink:type="simple" xlink:href="whg-20250630.xsd#LONGTERMINCENTIVECOMPENSATIONTables"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7b8b6408-484b-4e01-b3d1-571f9d2e2e08" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7b8b6408-484b-4e01-b3d1-571f9d2e2e08" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c53ec5ba-5381-4827-bd80-51071ce7a161" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_7b8b6408-484b-4e01-b3d1-571f9d2e2e08" xlink:to="loc_us-gaap_AwardTypeAxis_c53ec5ba-5381-4827-bd80-51071ce7a161" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c53ec5ba-5381-4827-bd80-51071ce7a161_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c53ec5ba-5381-4827-bd80-51071ce7a161" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c53ec5ba-5381-4827-bd80-51071ce7a161_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bee96914-3215-4990-ba3b-0912a63920e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c53ec5ba-5381-4827-bd80-51071ce7a161" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bee96914-3215-4990-ba3b-0912a63920e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectOnlyToServiceConditionMember_c976e269-e377-4645-8a6a-8a68508e6a38" xlink:href="whg-20250630.xsd#whg_RestrictedStockSubjectOnlyToServiceConditionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bee96914-3215-4990-ba3b-0912a63920e7" xlink:to="loc_whg_RestrictedStockSubjectOnlyToServiceConditionMember_c976e269-e377-4645-8a6a-8a68508e6a38" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_dfd20861-a425-44af-9ed0-ebb91b72460c" xlink:href="whg-20250630.xsd#whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_bee96914-3215-4990-ba3b-0912a63920e7" xlink:to="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_dfd20861-a425-44af-9ed0-ebb91b72460c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock_d74f00eb-cdd2-4d88-85c0-1b4c857f78b6" xlink:href="whg-20250630.xsd#whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:to="loc_whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock_d74f00eb-cdd2-4d88-85c0-1b4c857f78b6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_58c9609f-34c0-4718-a5bb-41654f01c5bf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_58c9609f-34c0-4718-a5bb-41654f01c5bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_08da961b-a7cf-4bec-8159-a7d3d0a0a41b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:to="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_08da961b-a7cf-4bec-8159-a7d3d0a0a41b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock_dc84e9f8-137f-45cf-8b72-503c1e3565df" xlink:href="whg-20250630.xsd#whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_e11d8424-5619-4ea6-a32f-e4bdc80705d6" xlink:to="loc_whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock_dc84e9f8-137f-45cf-8b72-503c1e3565df" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/EARNINGSPERSHAREDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#EARNINGSPERSHAREDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/EARNINGSPERSHAREDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_f86baa20-c2d6-45ab-830f-6713caa05d84" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_974cc25c-eabc-4f0b-8766-a0e988eca900" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_f86baa20-c2d6-45ab-830f-6713caa05d84" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_974cc25c-eabc-4f0b-8766-a0e988eca900" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_82ce109b-f3c4-47e5-872e-b81bd872b90b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_974cc25c-eabc-4f0b-8766-a0e988eca900" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_82ce109b-f3c4-47e5-872e-b81bd872b90b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_82ce109b-f3c4-47e5-872e-b81bd872b90b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_82ce109b-f3c4-47e5-872e-b81bd872b90b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_82ce109b-f3c4-47e5-872e-b81bd872b90b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_2dd836ed-371a-4cb7-8c1d-2220e8d7cc5b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_82ce109b-f3c4-47e5-872e-b81bd872b90b" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_2dd836ed-371a-4cb7-8c1d-2220e8d7cc5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_fe34b07d-d0f7-4c01-afea-f995cd5eefce" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_2dd836ed-371a-4cb7-8c1d-2220e8d7cc5b" xlink:to="loc_us-gaap_RestrictedStockMember_fe34b07d-d0f7-4c01-afea-f995cd5eefce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_c9f8bedd-2e51-47e5-bc17-a8c12eea98cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareLineItems_f86baa20-c2d6-45ab-830f-6713caa05d84" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_c9f8bedd-2e51-47e5-bc17-a8c12eea98cb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/INVESTMENTSDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#INVESTMENTSDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/INVESTMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_2e06265e-56aa-44c9-9d29-862fdee5134e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfAvailableForSaleSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_2e06265e-56aa-44c9-9d29-862fdee5134e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_9ac55641-dbf6-43c5-b935-edaa24146194" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_2e06265e-56aa-44c9-9d29-862fdee5134e" xlink:to="loc_us-gaap_InvestmentTypeAxis_9ac55641-dbf6-43c5-b935-edaa24146194" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_9ac55641-dbf6-43c5-b935-edaa24146194_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_9ac55641-dbf6-43c5-b935-edaa24146194" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_9ac55641-dbf6-43c5-b935-edaa24146194_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_9ac55641-dbf6-43c5-b935-edaa24146194" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_fe883935-7f38-46b9-8671-aaa440530d46" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_fe883935-7f38-46b9-8671-aaa440530d46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_97bbd5d2-d6d4-491f-b87f-930ca1f719d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MoneyMarketFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_MoneyMarketFundsMember_97bbd5d2-d6d4-491f-b87f-930ca1f719d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityFundsMember_d88c4700-72fb-4268-a1b0-08fc5c595c73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_EquityFundsMember_d88c4700-72fb-4268-a1b0-08fc5c595c73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_6204fb80-0c56-4b1e-a65c-dd99f1c36554" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_EquitySecuritiesMember_6204fb80-0c56-4b1e-a65c-dd99f1c36554" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UsGaap_EquitySecuritiesMemberMember_63237bb5-ddbf-4993-be44-cc3504bdc51a" xlink:href="whg-20250630.xsd#whg_UsGaap_EquitySecuritiesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_whg_UsGaap_EquitySecuritiesMemberMember_63237bb5-ddbf-4993-be44-cc3504bdc51a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsMember_7bd40dc7-f5d0-44a7-9ab5-8a7179761511" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrivateEquityFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_PrivateEquityFundsMember_7bd40dc7-f5d0-44a7-9ab5-8a7179761511" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_0b726ab2-a77d-4c78-8a26-a3874e6a4e9f" xlink:href="whg-20250630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_whg_PrivateEquityInvestmentsMember_0b726ab2-a77d-4c78-8a26-a3874e6a4e9f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExchangeTradedFundsMember_30e9d9ef-5d5e-4f69-ba70-6c6c1d429750" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ExchangeTradedFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_d2d8a2e6-7c91-42c1-9398-7007ceb654e2" xlink:to="loc_us-gaap_ExchangeTradedFundsMember_30e9d9ef-5d5e-4f69-ba70-6c6c1d429750" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_32b3d3b6-724d-43dd-b61c-11fd86ca87a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_2e06265e-56aa-44c9-9d29-862fdee5134e" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_32b3d3b6-724d-43dd-b61c-11fd86ca87a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_32b3d3b6-724d-43dd-b61c-11fd86ca87a2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_32b3d3b6-724d-43dd-b61c-11fd86ca87a2" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_32b3d3b6-724d-43dd-b61c-11fd86ca87a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_32b3d3b6-724d-43dd-b61c-11fd86ca87a2" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ZarvonaEnergyFundGPLPDomain_08aa620d-7e6b-4f87-bab6-1d691bfc5135" xlink:href="whg-20250630.xsd#whg_ZarvonaEnergyFundGPLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_ZarvonaEnergyFundGPLPDomain_08aa620d-7e6b-4f87-bab6-1d691bfc5135" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ZarvonaEnergyFundIIALPDomain_e9560411-67e0-4e57-8387-0ebdecdebdff" xlink:href="whg-20250630.xsd#whg_ZarvonaEnergyFundIIALPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_ZarvonaEnergyFundIIALPDomain_e9560411-67e0-4e57-8387-0ebdecdebdff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BroadmarkAssetManagementLLCDomain_05e54ba4-78dd-4ec5-9331-18e8b914dc52" xlink:href="whg-20250630.xsd#whg_BroadmarkAssetManagementLLCDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_BroadmarkAssetManagementLLCDomain_05e54ba4-78dd-4ec5-9331-18e8b914dc52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_SalientMLPTotalReturnFundLPDomain_d8fd147c-3de7-409c-8c22-e32ded29c888" xlink:href="whg-20250630.xsd#whg_SalientMLPTotalReturnFundLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_SalientMLPTotalReturnFundLPDomain_d8fd147c-3de7-409c-8c22-e32ded29c888" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_SalientMLPTotalReturnTEFundLPDomain_733a36e7-7ccb-46eb-92db-1f4a5bc8c6c0" xlink:href="whg-20250630.xsd#whg_SalientMLPTotalReturnTEFundLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_SalientMLPTotalReturnTEFundLPDomain_733a36e7-7ccb-46eb-92db-1f4a5bc8c6c0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalMember_248a440e-11a7-4c5b-a784-4499a577b40a" xlink:href="whg-20250630.xsd#whg_TotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_dec882ba-4bb9-42c9-ba48-a985afbe3178" xlink:to="loc_whg_TotalMember_248a440e-11a7-4c5b-a784-4499a577b40a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetRealizedOrUnrealizedGainLossOnTradingSecuritiesAbstract_117e940f-7d00-4009-93e8-3e78ff7afe75" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetRealizedOrUnrealizedGainLossOnTradingSecuritiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_NetRealizedOrUnrealizedGainLossOnTradingSecuritiesAbstract_117e940f-7d00-4009-93e8-3e78ff7afe75" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiGainLossAbstract_186e58c9-f643-4ccb-920c-a5dfa75689a3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiGainLossAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquitySecuritiesFvNiGainLossAbstract_186e58c9-f643-4ccb-920c-a5dfa75689a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_f3adbc17-2c76-401e-a159-6764d8d27b7e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrealizedGainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_f3adbc17-2c76-401e-a159-6764d8d27b7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedloss_f14eeea3-eed5-4228-a965-8ea3861ebf43" xlink:href="whg-20250630.xsd#whg_Investmentscarriedatfairvalueunrealizedloss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedloss_f14eeea3-eed5-4228-a965-8ea3861ebf43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_c430c447-d1cd-4cba-99cb-49c4369797f2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RealizedInvestmentGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_c430c447-d1cd-4cba-99cb-49c4369797f2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedgain_7097d620-e055-4839-bd4a-90adfa8bdff5" xlink:href="whg-20250630.xsd#whg_Investmentscarriedatfairvalueunrealizedgain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedgain_7097d620-e055-4839-bd4a-90adfa8bdff5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_90dee320-6cd7-436b-9444-f994bd536146" xlink:href="whg-20250630.xsd#whg_UnrealizedGainsLossesOnPrivateInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_90dee320-6cd7-436b-9444-f994bd536146" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostMethodInvestments_190094a3-4694-4f5c-8422-e08ccd8a9875" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_CostMethodInvestments_190094a3-4694-4f5c-8422-e08ccd8a9875" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_02ab1eb3-e9c8-4238-b670-fe04881cf463" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecuritiesDebtAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_02ab1eb3-e9c8-4238-b670-fe04881cf463" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingUnrealizedGain_e1ad65ef-ded4-4669-a218-cb594b9e44bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesTradingUnrealizedGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_DebtSecuritiesTradingUnrealizedGain_e1ad65ef-ded4-4669-a218-cb594b9e44bc" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingUnrealizedLoss_3baaf4da-d967-4a91-bd87-14b878dcde35" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesTradingUnrealizedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_DebtSecuritiesTradingUnrealizedLoss_3baaf4da-d967-4a91-bd87-14b878dcde35" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebt_15d05c2a-51be-4627-8357-3dd08b3ee886" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_TradingSecuritiesDebt_15d05c2a-51be-4627-8357-3dd08b3ee886" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCost_c05e635f-f49c-486a-b1d0-e2691beeaaef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCost_c05e635f-f49c-486a-b1d0-e2691beeaaef" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGain_496ed481-4392-44d3-9190-4b2ba647013c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGain_496ed481-4392-44d3-9190-4b2ba647013c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedLoss_67b5413d-95f1-41dd-ab2e-43b6c8cf78fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNiUnrealizedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedLoss_67b5413d-95f1-41dd-ab2e-43b6c8cf78fd" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_e671dbbf-ebfe-4eab-8585-732996612637" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNi"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_e671dbbf-ebfe-4eab-8585-732996612637" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost_aa9caf68-0d58-4b1c-b1d1-7c30dab4d5c4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost_aa9caf68-0d58-4b1c-b1d1-7c30dab4d5c4" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain_ff662c5c-0e8b-4935-9e91-1f25655bdc31" xlink:href="whg-20250630.xsd#whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain_ff662c5c-0e8b-4935-9e91-1f25655bdc31" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss_934e09bd-7b5d-481a-9776-aaddc2e2ad9a" xlink:href="whg-20250630.xsd#whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss_934e09bd-7b5d-481a-9776-aaddc2e2ad9a" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_abdc9631-494d-4226-b6b3-10f3892a016a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_TradingSecurities_abdc9631-494d-4226-b6b3-10f3892a016a" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_d86fb040-b8ff-4f56-a813-cc5cc58b2f76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_LongTermInvestments_d86fb040-b8ff-4f56-a813-cc5cc58b2f76" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_ba0fafbb-e78a-4cf2-8197-7d56ce9673ee" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_ba0fafbb-e78a-4cf2-8197-7d56ce9673ee" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongtermInvestmentsCarriedatFairValue_c3df76be-eff9-4e8b-a917-c565cbac2aed" xlink:href="whg-20250630.xsd#whg_LongtermInvestmentsCarriedatFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_LongtermInvestmentsCarriedatFairValue_c3df76be-eff9-4e8b-a917-c565cbac2aed" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_bfe21527-3238-4ea2-ab1c-e83fced36965" xlink:href="whg-20250630.xsd#whg_LongTermInvestmentsCarriedAtFairValueUsingNAV"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_bfe21527-3238-4ea2-ab1c-e83fced36965" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_6d83c789-9e35-434c-8db9-80fdf49ea312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_EquityMethodInvestments_6d83c789-9e35-434c-8db9-80fdf49ea312" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_a206af4c-24d0-4dc0-8170-1caf847ccdf5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_a206af4c-24d0-4dc0-8170-1caf847ccdf5" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentsUnderFairValueMeasurementAlternative_81b4286c-0991-49a7-a3b0-04d9c9680356" xlink:href="whg-20250630.xsd#whg_InvestmentsUnderFairValueMeasurementAlternative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_InvestmentsUnderFairValueMeasurementAlternative_81b4286c-0991-49a7-a3b0-04d9c9680356" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalInvestments_a5d5680b-79f5-4f9c-8a07-f611f39e94ad" xlink:href="whg-20250630.xsd#whg_TotalInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_TotalInvestments_a5d5680b-79f5-4f9c-8a07-f611f39e94ad" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestCloudPrivateInvestment_a7901025-846b-47dc-a2d3-319a0b8407f3" xlink:href="whg-20250630.xsd#whg_InvestCloudPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_InvestCloudPrivateInvestment_a7901025-846b-47dc-a2d3-319a0b8407f3" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueVista_c3ebd7af-db93-460e-b761-a4a588e5c99d" xlink:href="whg-20250630.xsd#whg_InvestmentCarryingValueVista"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_InvestmentCarryingValueVista_c3ebd7af-db93-460e-b761-a4a588e5c99d" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WEBsPreferredStock_49a82f1c-95da-44a1-9df2-3dd8ba30ad34" xlink:href="whg-20250630.xsd#whg_WEBsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_WEBsPreferredStock_49a82f1c-95da-44a1-9df2-3dd8ba30ad34" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WEBsCallOption_282e21cc-04ae-46a2-8127-8aef48045559" xlink:href="whg-20250630.xsd#whg_WEBsCallOption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_WEBsCallOption_282e21cc-04ae-46a2-8127-8aef48045559" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TXSEPrivateInvestment_6ee663bc-ae37-472d-a1c6-32de5614a4f4" xlink:href="whg-20250630.xsd#whg_TXSEPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_TXSEPrivateInvestment_6ee663bc-ae37-472d-a1c6-32de5614a4f4" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueRidgeline_59a8ac97-06dd-4976-bb27-9ebfb9f9b8e6" xlink:href="whg-20250630.xsd#whg_InvestmentCarryingValueRidgeline"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_InvestmentCarryingValueRidgeline_59a8ac97-06dd-4976-bb27-9ebfb9f9b8e6" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalInvestmentsUnderMeasurementAlternative_fbc3fd95-4e5c-4972-aa71-ba456c701e0c" xlink:href="whg-20250630.xsd#whg_TotalInvestmentsUnderMeasurementAlternative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_9c20f501-c540-4574-8d5c-fbd533f532de" xlink:to="loc_whg_TotalInvestmentsUnderMeasurementAlternative_fbc3fd95-4e5c-4972-aa71-ba456c701e0c" xlink:type="arc" order="34"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/INVESTMENTSDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#INVESTMENTSDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/INVESTMENTSDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfInvestmentsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfInvestmentsTable_5dd028ef-8b0d-4dd8-87d3-9fd7463287c8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfInvestmentsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_5dd028ef-8b0d-4dd8-87d3-9fd7463287c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_153af7c2-2b16-4f25-94c5-ac644b67e53f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_5dd028ef-8b0d-4dd8-87d3-9fd7463287c8" xlink:to="loc_srt_ConsolidatedEntitiesAxis_153af7c2-2b16-4f25-94c5-ac644b67e53f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_153af7c2-2b16-4f25-94c5-ac644b67e53f_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_153af7c2-2b16-4f25-94c5-ac644b67e53f" xlink:to="loc_srt_ConsolidatedEntitiesDomain_153af7c2-2b16-4f25-94c5-ac644b67e53f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_72473ca2-8856-4c56-8ffb-aeaf1373dde0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_153af7c2-2b16-4f25-94c5-ac644b67e53f" xlink:to="loc_srt_ConsolidatedEntitiesDomain_72473ca2-8856-4c56-8ffb-aeaf1373dde0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityMember_84bfc686-b864-4150-87f7-094127627e82" xlink:href="whg-20250630.xsd#whg_VariableInterestEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_72473ca2-8856-4c56-8ffb-aeaf1373dde0" xlink:to="loc_whg_VariableInterestEntityMember_84bfc686-b864-4150-87f7-094127627e82" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_2f45575d-9204-41a1-8e76-66eda6995b3d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfInvestmentsTable_5dd028ef-8b0d-4dd8-87d3-9fd7463287c8" xlink:to="loc_us-gaap_InvestmentTypeAxis_2f45575d-9204-41a1-8e76-66eda6995b3d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_2f45575d-9204-41a1-8e76-66eda6995b3d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_2f45575d-9204-41a1-8e76-66eda6995b3d" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_2f45575d-9204-41a1-8e76-66eda6995b3d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_6f8ebb2d-ad9d-4fac-86d7-23e6c02e7901" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_2f45575d-9204-41a1-8e76-66eda6995b3d" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_6f8ebb2d-ad9d-4fac-86d7-23e6c02e7901" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UsGaap_EquitySecuritiesMemberMember_417ddeba-0ee2-430b-b1b3-8f0c3f9a35f5" xlink:href="whg-20250630.xsd#whg_UsGaap_EquitySecuritiesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_6f8ebb2d-ad9d-4fac-86d7-23e6c02e7901" xlink:to="loc_whg_UsGaap_EquitySecuritiesMemberMember_417ddeba-0ee2-430b-b1b3-8f0c3f9a35f5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_dac478ec-e9f6-4395-a6f7-218098c07651" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_LongTermInvestments_dac478ec-e9f6-4395-a6f7-218098c07651" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_0d64d815-e897-43b1-a526-3d2579b8e471" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_TradingSecurities_0d64d815-e897-43b1-a526-3d2579b8e471" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainOnSecurities_6e32f352-1141-47af-9517-dc1ff9d01435" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_UnrealizedGainOnSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_UnrealizedGainOnSecurities_6e32f352-1141-47af-9517-dc1ff9d01435" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_48eb27ab-6eb7-4d5f-8f2a-3456e7769d77" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GainLossOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_GainLossOnInvestments_48eb27ab-6eb7-4d5f-8f2a-3456e7769d77" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedgain_5d647649-b9a7-4fc6-ac87-3f99cd6be7d9" xlink:href="whg-20250630.xsd#whg_Investmentscarriedatfairvalueunrealizedgain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedgain_5d647649-b9a7-4fc6-ac87-3f99cd6be7d9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_1b042537-772e-451b-9876-e3d8a2586dc9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecuritiesDebtAmortizedCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_1b042537-772e-451b-9876-e3d8a2586dc9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_3e153bbd-4e3f-4da6-94bc-1ca581f1282c" xlink:href="whg-20250630.xsd#whg_UnrealizedGainsLossesOnPrivateInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_3e153bbd-4e3f-4da6-94bc-1ca581f1282c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostMethodInvestments_f3e6682c-fcc0-46fc-82c3-0f60ce2bcd62" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CostMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_CostMethodInvestments_f3e6682c-fcc0-46fc-82c3-0f60ce2bcd62" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_4544051d-8371-4a98-afaf-affd64c9dcc5" xlink:href="whg-20250630.xsd#whg_LongTermInvestmentsCarriedAtFairValueUsingNAV"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_4544051d-8371-4a98-afaf-affd64c9dcc5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_fed766db-c67b-47d5-9072-d2e3d22b27a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_fed766db-c67b-47d5-9072-d2e3d22b27a8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestment_4551806f-14cb-4740-a7a7-e8b5b3976dcd" xlink:href="whg-20250630.xsd#whg_CarryingValuePrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_CarryingValuePrivateInvestment_4551806f-14cb-4740-a7a7-e8b5b3976dcd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueVista_f3897cc1-322f-4bae-b996-1cfe3eec43ef" xlink:href="whg-20250630.xsd#whg_InvestmentCarryingValueVista"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_InvestmentCarryingValueVista_f3897cc1-322f-4bae-b996-1cfe3eec43ef" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestmentTxStockExchange_1d3d936f-aaaf-41fd-b049-e937c3805167" xlink:href="whg-20250630.xsd#whg_CarryingValuePrivateInvestmentTxStockExchange"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_CarryingValuePrivateInvestmentTxStockExchange_1d3d936f-aaaf-41fd-b049-e937c3805167" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestmentFunds_f297ee2f-d821-4afa-a1b6-69c3e64abd9e" xlink:href="whg-20250630.xsd#whg_CarryingValuePrivateInvestmentFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_a31b9563-ec0a-46b5-995f-f4f9677facda" xlink:to="loc_whg_CarryingValuePrivateInvestmentFunds_f297ee2f-d821-4afa-a1b6-69c3e64abd9e" xlink:type="arc" order="13"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#FAIRVALUEMEASUREMENTSDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_db46c010-e98b-451b-9330-a42c00414136" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_db46c010-e98b-451b-9330-a42c00414136" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_7091712e-a277-4dc1-b791-8f519c2831b1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_db46c010-e98b-451b-9330-a42c00414136" xlink:to="loc_us-gaap_InvestmentTypeAxis_7091712e-a277-4dc1-b791-8f519c2831b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_7091712e-a277-4dc1-b791-8f519c2831b1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InvestmentTypeAxis_7091712e-a277-4dc1-b791-8f519c2831b1" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_7091712e-a277-4dc1-b791-8f519c2831b1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_19e6b9c6-06ed-44df-9a72-2f6e56fdbc82" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentTypeCategorizationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InvestmentTypeAxis_7091712e-a277-4dc1-b791-8f519c2831b1" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_19e6b9c6-06ed-44df-9a72-2f6e56fdbc82" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsMember_f715430c-2a69-4fe7-b461-38677903455d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PrivateEquityFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_19e6b9c6-06ed-44df-9a72-2f6e56fdbc82" xlink:to="loc_us-gaap_PrivateEquityFundsMember_f715430c-2a69-4fe7-b461-38677903455d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_891c1aca-1f6e-43c4-8251-25706fcaef69" xlink:href="whg-20250630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_19e6b9c6-06ed-44df-9a72-2f6e56fdbc82" xlink:to="loc_whg_PrivateEquityInvestmentsMember_891c1aca-1f6e-43c4-8251-25706fcaef69" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2a40bf3-9814-4cc5-8e29-ca6f1422f188" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_db46c010-e98b-451b-9330-a42c00414136" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2a40bf3-9814-4cc5-8e29-ca6f1422f188" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2a40bf3-9814-4cc5-8e29-ca6f1422f188_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2a40bf3-9814-4cc5-8e29-ca6f1422f188" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2a40bf3-9814-4cc5-8e29-ca6f1422f188_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2a40bf3-9814-4cc5-8e29-ca6f1422f188" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_5cb561f2-bafb-48eb-8e0a-1074e3f28f79" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_5cb561f2-bafb-48eb-8e0a-1074e3f28f79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_7d908001-d3b1-4558-8bb0-5ad697ada2b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_7d908001-d3b1-4558-8bb0-5ad697ada2b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_09369ade-ec2e-4794-a715-ef9109374dd1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_09369ade-ec2e-4794-a715-ef9109374dd1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_0c61b2ce-f2c0-4162-824c-2f5fbaa0981a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_0c61b2ce-f2c0-4162-824c-2f5fbaa0981a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_50d5e4ee-1ca1-4c77-9e24-b9beec0142f1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsRecurringMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_02fd84a8-9942-4254-8464-46df0fe87d6a" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_50d5e4ee-1ca1-4c77-9e24-b9beec0142f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentsFairValueDisclosureAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebt_cdc66564-1ffa-49de-97cc-10426b4262cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecuritiesDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:to="loc_us-gaap_TradingSecuritiesDebt_cdc66564-1ffa-49de-97cc-10426b4262cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_bea98107-2611-4430-89eb-063526327d22" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquitySecuritiesFvNi"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_bea98107-2611-4430-89eb-063526327d22" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_92b3ade0-c572-4db4-b06f-7fc802523374" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:to="loc_us-gaap_TradingSecurities_92b3ade0-c572-4db4-b06f-7fc802523374" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityFairValueByFairValueHierarchyLevelExtensibleList_aec87229-2dad-4c91-891f-267bd8887745" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationContingentConsiderationLiabilityFairValueByFairValueHierarchyLevelExtensibleList"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityFairValueByFairValueHierarchyLevelExtensibleList_aec87229-2dad-4c91-891f-267bd8887745" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_00947b6f-6f18-42d1-811f-72db97b57aaf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherLiabilitiesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_9d75aa3f-5f80-4d83-a8ed-4a0eb41f709b" xlink:to="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_00947b6f-6f18-42d1-811f-72db97b57aaf" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_95f1a0ac-777c-419e-8002-3bbbbdda61b5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_95f1a0ac-777c-419e-8002-3bbbbdda61b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_6fef5bcd-02c2-4596-8937-9307569d3dd3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_6fef5bcd-02c2-4596-8937-9307569d3dd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_0384fda9-2248-4dcb-8916-ee611925e90f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease_a2d96e32-7f69-4f51-999c-c91183fdd99c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease_a2d96e32-7f69-4f51-999c-c91183fdd99c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_02ff3e75-a4dc-4fc5-80c3-a87e14fff5d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_51d8f536-c0c4-498a-833a-af9e31954914" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_02ff3e75-a4dc-4fc5-80c3-a87e14fff5d4" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_FairValueInputsAbstract_cc0e72c7-5fd5-4246-b0b8-36fe124b775f" xlink:href="whg-20250630.xsd#whg_FairValueInputsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_FairValueInputsAbstract_cc0e72c7-5fd5-4246-b0b8-36fe124b775f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsSensitivityAnalysisDescription_bc588dcb-ec07-466a-96fb-3d5213d37bc6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementsSensitivityAnalysisDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_FairValueMeasurementsSensitivityAnalysisDescription_bc588dcb-ec07-466a-96fb-3d5213d37bc6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleMinimum_9f95398b-9c11-461d-b48c-000e1698f1e8" xlink:href="whg-20250630.xsd#whg_UnobservableInputBookValueMultipleMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputBookValueMultipleMinimum_9f95398b-9c11-461d-b48c-000e1698f1e8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleMaximum_e30c37ad-eb6a-4a2b-a6ac-4e0f7d691452" xlink:href="whg-20250630.xsd#whg_UnobservableInputBookValueMultipleMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputBookValueMultipleMaximum_e30c37ad-eb6a-4a2b-a6ac-4e0f7d691452" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleWeightedAverage_915f8fe9-9029-497b-a161-0a054037a905" xlink:href="whg-20250630.xsd#whg_UnobservableInputBookValueMultipleWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputBookValueMultipleWeightedAverage_915f8fe9-9029-497b-a161-0a054037a905" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_6b1d4cd5-90e3-44e1-810f-de36894429c2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LongTermInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_LongTermInvestments_6b1d4cd5-90e3-44e1-810f-de36894429c2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_e0bfb804-5f18-43d7-a108-5477859e8fea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_e0bfb804-5f18-43d7-a108-5477859e8fea" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_b07c57e9-f741-40e2-a44e-b33dfbdd45e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_b07c57e9-f741-40e2-a44e-b33dfbdd45e7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_1a28f2ea-30fe-4af1-8de5-98e6f480dc8b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_1a28f2ea-30fe-4af1-8de5-98e6f480dc8b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateMaximum_a4a39b06-6ce5-4091-8062-533d0f64288e" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateMaximum_a4a39b06-6ce5-4091-8062-533d0f64288e" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage_e84b2ed6-cad2-41e5-a6fc-1a982ba5419b" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage_e84b2ed6-cad2-41e5-a6fc-1a982ba5419b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateMinimum_346270fa-71c0-4621-9317-9c635c0f18cf" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateMinimum_346270fa-71c0-4621-9317-9c635c0f18cf" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage_7cbdc5bf-5b10-4c5a-a5fc-13ba855d4d15" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage_7cbdc5bf-5b10-4c5a-a5fc-13ba855d4d15" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityMaximum_580fd8b1-e52e-4007-9c46-6f0bf213bbae" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionVolatilityMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityMaximum_580fd8b1-e52e-4007-9c46-6f0bf213bbae" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityMinimum_da017641-13da-470e-979d-4765aff2f8df" xlink:href="whg-20250630.xsd#whg_UnobservableInputRevenueRetentionVolatilityMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityMinimum_da017641-13da-470e-979d-4765aff2f8df" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateWeightedAverage_6620e9df-8d75-4879-8b0b-d878d84b0521" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthDiscountRateWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateWeightedAverage_6620e9df-8d75-4879-8b0b-d878d84b0521" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateMaximum_3560438d-dafb-40e4-b754-9b672f6fed50" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthDiscountRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateMaximum_3560438d-dafb-40e4-b754-9b672f6fed50" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateMinimum_060d15ce-a192-4198-88c6-dadd321a81ae" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthDiscountRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateMinimum_060d15ce-a192-4198-88c6-dadd321a81ae" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityWeightedAverage_149babe7-68b8-49a5-b1d0-f20a51d5407c" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthVolatilityWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthVolatilityWeightedAverage_149babe7-68b8-49a5-b1d0-f20a51d5407c" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityMaximum_f5a75f71-8f91-4bb6-a221-cc5241a2c4b8" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthVolatilityMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthVolatilityMaximum_f5a75f71-8f91-4bb6-a221-cc5241a2c4b8" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityMinimum_157b3c13-263d-436b-9395-3d28306cd0d2" xlink:href="whg-20250630.xsd#whg_UnobservableInputGrowthVolatilityMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_whg_UnobservableInputGrowthVolatilityMinimum_157b3c13-263d-436b-9395-3d28306cd0d2" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferredContingentConsideration_8dc5bfc4-c774-411b-a5c0-6f2072be720e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionConsiderationTransferredContingentConsideration"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_af835ebc-bcd8-4b1a-aed9-4365b1a01afb" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferredContingentConsideration_8dc5bfc4-c774-411b-a5c0-6f2072be720e" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/GOODWILLANDOTHERINTANGIBLEASSETSDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#GOODWILLANDOTHERINTANGIBLEASSETSDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/GOODWILLANDOTHERINTANGIBLEASSETSDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_9a1272d5-bc15-45ce-be8b-a364ef086207" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_9a1272d5-bc15-45ce-be8b-a364ef086207" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_67dd7d30-ae03-4fd1-91f2-41609d0cafa0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_9a1272d5-bc15-45ce-be8b-a364ef086207" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_67dd7d30-ae03-4fd1-91f2-41609d0cafa0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_67dd7d30-ae03-4fd1-91f2-41609d0cafa0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_67dd7d30-ae03-4fd1-91f2-41609d0cafa0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_67dd7d30-ae03-4fd1-91f2-41609d0cafa0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_d8681db1-eb78-4e79-a354-4c6212ffa4e8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_67dd7d30-ae03-4fd1-91f2-41609d0cafa0" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_d8681db1-eb78-4e79-a354-4c6212ffa4e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustSegmentGoodwill_830647dd-a0c3-4e70-87d8-5e7c487823c4" xlink:href="whg-20250630.xsd#whg_TrustSegmentGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_whg_TrustSegmentGoodwill_830647dd-a0c3-4e70-87d8-5e7c487823c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisorySegmentGoodwill_efb1c135-adea-4350-9333-e6b364177dec" xlink:href="whg-20250630.xsd#whg_AdvisorySegmentGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_whg_AdvisorySegmentGoodwill_efb1c135-adea-4350-9333-e6b364177dec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BalanceAtDecember312021_99b8c35a-1b1d-4194-bc12-782df5785e8c" xlink:href="whg-20250630.xsd#whg_BalanceAtDecember312021"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_whg_BalanceAtDecember312021_99b8c35a-1b1d-4194-bc12-782df5785e8c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_acb76f87-2cea-4a71-aa78-90d25cbd4522" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_acb76f87-2cea-4a71-aa78-90d25cbd4522" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AcquiredGoodwillTotal_45fec2bb-c89f-431a-97d6-b30f8747aef4" xlink:href="whg-20250630.xsd#whg_AcquiredGoodwillTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_whg_AcquiredGoodwillTotal_45fec2bb-c89f-431a-97d6-b30f8747aef4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_8a90dcc7-672b-4841-94af-790f1cf01ff5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GoodwillPurchaseAccountingAdjustments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_8a90dcc7-672b-4841-94af-790f1cf01ff5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_GoodwillAdjustmentsTotal_c5e54363-85a4-4d30-8ef9-7050cd5bc024" xlink:href="whg-20250630.xsd#whg_GoodwillAdjustmentsTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_whg_GoodwillAdjustmentsTotal_c5e54363-85a4-4d30-8ef9-7050cd5bc024" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_96e58d31-5fc6-41a4-8e90-f79b4c04c514" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_96e58d31-5fc6-41a4-8e90-f79b4c04c514" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentForAmortization_5cf4192d-f4de-4ceb-8974-d33b341cbb5e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AdjustmentForAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_9498553e-1dd1-4af9-ad1b-b1c1d2242e3a" xlink:to="loc_us-gaap_AdjustmentForAmortization_5cf4192d-f4de-4ceb-8974-d33b341cbb5e" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#VARIABLEINTERESTENTITIESDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_889ab659-a6eb-453b-9144-b0f296ccdfa9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_ccb18b49-64b6-4012-9051-7c56ce0e9b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_889ab659-a6eb-453b-9144-b0f296ccdfa9" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_ccb18b49-64b6-4012-9051-7c56ce0e9b3a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_7a7c8124-a444-4157-aba9-61aa4c703f28" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_ccb18b49-64b6-4012-9051-7c56ce0e9b3a" xlink:to="loc_srt_ConsolidatedEntitiesAxis_7a7c8124-a444-4157-aba9-61aa4c703f28" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7a7c8124-a444-4157-aba9-61aa4c703f28_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_7a7c8124-a444-4157-aba9-61aa4c703f28" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7a7c8124-a444-4157-aba9-61aa4c703f28_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_bdbd55a7-5dfa-48ca-b952-374facf01f4f" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_7a7c8124-a444-4157-aba9-61aa4c703f28" xlink:to="loc_srt_ConsolidatedEntitiesDomain_bdbd55a7-5dfa-48ca-b952-374facf01f4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityMember_61d7f80a-75ed-438b-93ed-34c219f82fa4" xlink:href="whg-20250630.xsd#whg_VariableInterestEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_bdbd55a7-5dfa-48ca-b952-374facf01f4f" xlink:to="loc_whg_VariableInterestEntityMember_61d7f80a-75ed-438b-93ed-34c219f82fa4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CommonTrustFundsMember_7b8d0b4c-9ee4-4007-b940-1b7aff481da4" xlink:href="whg-20250630.xsd#whg_CommonTrustFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_bdbd55a7-5dfa-48ca-b952-374facf01f4f" xlink:to="loc_whg_CommonTrustFundsMember_7b8d0b4c-9ee4-4007-b940-1b7aff481da4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_f122befb-ccd8-4da4-81c2-4a850a066080" xlink:href="whg-20250630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_bdbd55a7-5dfa-48ca-b952-374facf01f4f" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_f122befb-ccd8-4da4-81c2-4a850a066080" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_05ae817a-ac9b-4c9c-8e25-71f154b4a356" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_889ab659-a6eb-453b-9144-b0f296ccdfa9" xlink:to="loc_us-gaap_TradingSecurities_05ae817a-ac9b-4c9c-8e25-71f154b4a356" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityRevenues_cf348e3a-51bf-4de9-9388-e163b40eb8d8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityRevenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_889ab659-a6eb-453b-9144-b0f296ccdfa9" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityRevenues_cf348e3a-51bf-4de9-9388-e163b40eb8d8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_77647706-2269-4d92-9c36-451cd264ca09" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentOwnedAtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_889ab659-a6eb-453b-9144-b0f296ccdfa9" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_77647706-2269-4d92-9c36-451cd264ca09" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#VARIABLEINTERESTENTITIESDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_bc3562ec-fd62-4c02-aa10-9b9228622488" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_bb61802e-7a0b-405c-af47-7e3c355234cb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_bc3562ec-fd62-4c02-aa10-9b9228622488" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_bb61802e-7a0b-405c-af47-7e3c355234cb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_eabf02e8-3f59-4382-b421-ef21072ad4af" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_bb61802e-7a0b-405c-af47-7e3c355234cb" xlink:to="loc_srt_ConsolidatedEntitiesAxis_eabf02e8-3f59-4382-b421-ef21072ad4af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_eabf02e8-3f59-4382-b421-ef21072ad4af_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_eabf02e8-3f59-4382-b421-ef21072ad4af" xlink:to="loc_srt_ConsolidatedEntitiesDomain_eabf02e8-3f59-4382-b421-ef21072ad4af_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_eabf02e8-3f59-4382-b421-ef21072ad4af" xlink:to="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodFundsMember_c0199bf1-8d7a-406c-bed4-e942b048f36f" xlink:href="whg-20250630.xsd#whg_WestwoodFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_WestwoodFundsMember_c0199bf1-8d7a-406c-bed4-e942b048f36f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CommonTrustFundsMember_06356c4a-8160-4925-bb74-9b77428c935a" xlink:href="whg-20250630.xsd#whg_CommonTrustFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_CommonTrustFundsMember_06356c4a-8160-4925-bb74-9b77428c935a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_416f92dc-c0f9-41fb-b403-102588e0c94d" xlink:href="whg-20250630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_416f92dc-c0f9-41fb-b403-102588e0c94d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodHospitalityFundILLCMember_6f92a3c3-f417-4ded-b800-f37608ccdb91" xlink:href="whg-20250630.xsd#whg_WestwoodHospitalityFundILLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_WestwoodHospitalityFundILLCMember_6f92a3c3-f417-4ded-b800-f37608ccdb91" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_0cdaa55c-44ff-4a3f-9e94-220f0d9a26dc" xlink:href="whg-20250630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_PrivateEquityInvestmentsMember_0cdaa55c-44ff-4a3f-9e94-220f0d9a26dc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateWealthMember_a39a9a2c-07e5-47df-b5e2-c8193000ac46" xlink:href="whg-20250630.xsd#whg_PrivateWealthMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_PrivateWealthMember_a39a9a2c-07e5-47df-b5e2-c8193000ac46" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InstitutionalMember_70136e3b-ae7c-4894-a1b5-f6eebc84ae10" xlink:href="whg-20250630.xsd#whg_InstitutionalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_507f3992-97e4-4096-8886-713ea3bed3ec" xlink:to="loc_whg_InstitutionalMember_70136e3b-ae7c-4894-a1b5-f6eebc84ae10" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_13ea0849-e346-41b9-921c-933fafeba8a9" xlink:href="whg-20250630.xsd#whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_bc3562ec-fd62-4c02-aa10-9b9228622488" xlink:to="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_13ea0849-e346-41b9-921c-933fafeba8a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsUnderManagementCarryingAmount_d94c6cdd-f6c8-4261-85ab-da85fb88dea3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetsUnderManagementCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_13ea0849-e346-41b9-921c-933fafeba8a9" xlink:to="loc_us-gaap_AssetsUnderManagementCarryingAmount_d94c6cdd-f6c8-4261-85ab-da85fb88dea3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_9b9f57b5-7f3d-476b-b2ac-f4b7532e0bea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TradingSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_13ea0849-e346-41b9-921c-933fafeba8a9" xlink:to="loc_us-gaap_TradingSecurities_9b9f57b5-7f3d-476b-b2ac-f4b7532e0bea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RiskOfLoss_86b4c001-8337-47e1-8d88-2e238ffed5bd" xlink:href="whg-20250630.xsd#whg_RiskOfLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_13ea0849-e346-41b9-921c-933fafeba8a9" xlink:to="loc_whg_RiskOfLoss_86b4c001-8337-47e1-8d88-2e238ffed5bd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityConsolidatedAssetsNoncurrent_8c3caec8-eb38-48dd-a937-7a4e477ea624" xlink:href="whg-20250630.xsd#whg_VariableInterestEntityConsolidatedAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_bc3562ec-fd62-4c02-aa10-9b9228622488" xlink:to="loc_whg_VariableInterestEntityConsolidatedAssetsNoncurrent_8c3caec8-eb38-48dd-a937-7a4e477ea624" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/REVENUEDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#REVENUEDisaggregationofRevenueDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/REVENUEDisaggregationofRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_78ded2c5-16e4-4c62-8ad1-29e37908c522" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_78ded2c5-16e4-4c62-8ad1-29e37908c522" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_19dc99b7-1664-4fd5-b1a9-d03c20591163" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:to="loc_srt_ProductOrServiceAxis_19dc99b7-1664-4fd5-b1a9-d03c20591163" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_19dc99b7-1664-4fd5-b1a9-d03c20591163_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_19dc99b7-1664-4fd5-b1a9-d03c20591163" xlink:to="loc_srt_ProductsAndServicesDomain_19dc99b7-1664-4fd5-b1a9-d03c20591163_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_19dc99b7-1664-4fd5-b1a9-d03c20591163" xlink:to="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentAdvisoryServicesMember_9cb0aa9b-46d4-4885-b823-b3823e8226cd" xlink:href="whg-20250630.xsd#whg_InvestmentAdvisoryServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_InvestmentAdvisoryServicesMember_9cb0aa9b-46d4-4885-b823-b3823e8226cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundAdvisoryMemberMember_71a16831-6645-403f-bf2d-17fd7268e903" xlink:href="whg-20250630.xsd#whg_MutualFundAdvisoryMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_MutualFundAdvisoryMemberMember_71a16831-6645-403f-bf2d-17fd7268e903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateWealthAdvisoryMember_a2fb8638-6f95-4df7-b596-7be6ef7356ee" xlink:href="whg-20250630.xsd#whg_PrivateWealthAdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_PrivateWealthAdvisoryMember_a2fb8638-6f95-4df7-b596-7be6ef7356ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PerformancefeeMember_f52425f6-ee38-4094-89b5-d18c3e66ce3a" xlink:href="whg-20250630.xsd#whg_PerformancefeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_PerformancefeeMember_f52425f6-ee38-4094-89b5-d18c3e66ce3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustFeeMember_841b8c21-3278-42df-9724-edf621b25b2e" xlink:href="whg-20250630.xsd#whg_TrustFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_TrustFeeMember_841b8c21-3278-42df-9724-edf621b25b2e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_OtherRevenueMiscServicesMember_044db83a-6175-4cb6-9b63-6f003eb0361e" xlink:href="whg-20250630.xsd#whg_OtherRevenueMiscServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_OtherRevenueMiscServicesMember_044db83a-6175-4cb6-9b63-6f003eb0361e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedMember_fa1ebe58-755b-4f3e-a763-b2bcb673296b" xlink:href="whg-20250630.xsd#whg_TrustPerformanceBasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_3b104601-7271-4a32-91de-42d15db681c0" xlink:to="loc_whg_TrustPerformanceBasedMember_fa1ebe58-755b-4f3e-a763-b2bcb673296b" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_dba036ba-aa90-47a7-86bb-fe194e013216" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_dba036ba-aa90-47a7-86bb-fe194e013216" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_dba036ba-aa90-47a7-86bb-fe194e013216_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_dba036ba-aa90-47a7-86bb-fe194e013216" xlink:to="loc_us-gaap_SegmentDomain_dba036ba-aa90-47a7-86bb-fe194e013216_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_a16e26cd-70f2-49d8-930f-df7dc857c42e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_dba036ba-aa90-47a7-86bb-fe194e013216" xlink:to="loc_us-gaap_SegmentDomain_a16e26cd-70f2-49d8-930f-df7dc857c42e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustMember_9cf215ca-ec84-4727-84df-7357e2d61d39" xlink:href="whg-20250630.xsd#whg_TrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_a16e26cd-70f2-49d8-930f-df7dc857c42e" xlink:to="loc_whg_TrustMember_9cf215ca-ec84-4727-84df-7357e2d61d39" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisoryMember_039c26a8-ba37-4b50-8a2d-cf5d43433032" xlink:href="whg-20250630.xsd#whg_AdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_a16e26cd-70f2-49d8-930f-df7dc857c42e" xlink:to="loc_whg_AdvisoryMember_039c26a8-ba37-4b50-8a2d-cf5d43433032" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelAxis_367af79f-8539-4881-8b04-81226302e9db" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerSalesChannelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelAxis_367af79f-8539-4881-8b04-81226302e9db" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelDomain_367af79f-8539-4881-8b04-81226302e9db_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerSalesChannelDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ContractWithCustomerSalesChannelAxis_367af79f-8539-4881-8b04-81226302e9db" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelDomain_367af79f-8539-4881-8b04-81226302e9db_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelDomain_e8dbd9ac-d361-4c99-a167-ebbe131e5694" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ContractWithCustomerSalesChannelDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ContractWithCustomerSalesChannelAxis_367af79f-8539-4881-8b04-81226302e9db" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelDomain_e8dbd9ac-d361-4c99-a167-ebbe131e5694" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_96972063-8d28-49fb-86fa-de215275a97b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_468a051b-887d-454a-b724-05f671c62f73" xlink:to="loc_srt_StatementGeographicalAxis_96972063-8d28-49fb-86fa-de215275a97b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_96972063-8d28-49fb-86fa-de215275a97b_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_96972063-8d28-49fb-86fa-de215275a97b" xlink:to="loc_srt_SegmentGeographicalDomain_96972063-8d28-49fb-86fa-de215275a97b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_5c1ab31d-fdbd-43e0-8972-5bc21940728a" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_96972063-8d28-49fb-86fa-de215275a97b" xlink:to="loc_srt_SegmentGeographicalDomain_5c1ab31d-fdbd-43e0-8972-5bc21940728a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_af3e5886-eac1-431d-a4cb-282e5369469d" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5c1ab31d-fdbd-43e0-8972-5bc21940728a" xlink:to="loc_srt_EuropeMember_af3e5886-eac1-431d-a4cb-282e5369469d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_b17ea63c-a834-4875-a87b-9d241f52366e" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5c1ab31d-fdbd-43e0-8972-5bc21940728a" xlink:to="loc_country_CA_b17ea63c-a834-4875-a87b-9d241f52366e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_34408748-1953-4989-b05e-d13480c395b1" xlink:href="https://xbrl.sec.gov/country/2025/country-2025.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_5c1ab31d-fdbd-43e0-8972-5bc21940728a" xlink:to="loc_country_US_34408748-1953-4989-b05e-d13480c395b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_5b18dba1-2c37-4662-9f34-67148439a9d4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_78ded2c5-16e4-4c62-8ad1-29e37908c522" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_5b18dba1-2c37-4662-9f34-67148439a9d4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#LONGTERMINCENTIVECOMPENSATIONDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_b9f2f324-85fc-47e4-aadd-150f3796d490" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_us-gaap_VestingAxis_b9f2f324-85fc-47e4-aadd-150f3796d490" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_b9f2f324-85fc-47e4-aadd-150f3796d490_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_b9f2f324-85fc-47e4-aadd-150f3796d490" xlink:to="loc_us-gaap_VestingDomain_b9f2f324-85fc-47e4-aadd-150f3796d490_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_eb080d8f-be63-41b5-ba72-80faed9f050f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_b9f2f324-85fc-47e4-aadd-150f3796d490" xlink:to="loc_us-gaap_VestingDomain_eb080d8f-be63-41b5-ba72-80faed9f050f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetAxis_89f07b33-d5a3-4fe6-9683-a6f3a0828931" xlink:href="whg-20250630.xsd#whg_TargetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_whg_TargetAxis_89f07b33-d5a3-4fe6-9683-a6f3a0828931" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetDomain_89f07b33-d5a3-4fe6-9683-a6f3a0828931_default" xlink:href="whg-20250630.xsd#whg_TargetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_whg_TargetAxis_89f07b33-d5a3-4fe6-9683-a6f3a0828931" xlink:to="loc_whg_TargetDomain_89f07b33-d5a3-4fe6-9683-a6f3a0828931_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetDomain_52999a0d-6c68-4f0e-9c02-84e9a4025f72" xlink:href="whg-20250630.xsd#whg_TargetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_whg_TargetAxis_89f07b33-d5a3-4fe6-9683-a6f3a0828931" xlink:to="loc_whg_TargetDomain_52999a0d-6c68-4f0e-9c02-84e9a4025f72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_e4993715-885c-4220-bdfd-f599b82228a1" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_srt_RangeAxis_e4993715-885c-4220-bdfd-f599b82228a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e4993715-885c-4220-bdfd-f599b82228a1_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_e4993715-885c-4220-bdfd-f599b82228a1" xlink:to="loc_srt_RangeMember_e4993715-885c-4220-bdfd-f599b82228a1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_8d3478ca-7588-412b-8b07-e258afa26e9b" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_e4993715-885c-4220-bdfd-f599b82228a1" xlink:to="loc_srt_RangeMember_8d3478ca-7588-412b-8b07-e258afa26e9b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c67efe5d-fa9c-4edd-99e1-57d3c0424da1" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_us-gaap_AwardTypeAxis_c67efe5d-fa9c-4edd-99e1-57d3c0424da1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c67efe5d-fa9c-4edd-99e1-57d3c0424da1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c67efe5d-fa9c-4edd-99e1-57d3c0424da1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c67efe5d-fa9c-4edd-99e1-57d3c0424da1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc1d93a1-690f-490c-b614-59a07a9a2d03" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c67efe5d-fa9c-4edd-99e1-57d3c0424da1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc1d93a1-690f-490c-b614-59a07a9a2d03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_703444ab-a7bc-45d3-ae6a-9ace7597ad12" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc1d93a1-690f-490c-b614-59a07a9a2d03" xlink:to="loc_us-gaap_RestrictedStockMember_703444ab-a7bc-45d3-ae6a-9ace7597ad12" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CanadianPlanMember_44752f7e-bde7-48ec-b9bb-0adb6fd44b09" xlink:href="whg-20250630.xsd#whg_CanadianPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc1d93a1-690f-490c-b614-59a07a9a2d03" xlink:to="loc_whg_CanadianPlanMember_44752f7e-bde7-48ec-b9bb-0adb6fd44b09" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundShareIncentiveAwardsMember_7fbb1737-5d31-4a06-8c02-8b0cfd6ba312" xlink:href="whg-20250630.xsd#whg_MutualFundShareIncentiveAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_cc1d93a1-690f-490c-b614-59a07a9a2d03" xlink:to="loc_whg_MutualFundShareIncentiveAwardsMember_7fbb1737-5d31-4a06-8c02-8b0cfd6ba312" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_2d6b60a8-dd45-49db-815c-422f99c212ac" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_dei_LegalEntityAxis_2d6b60a8-dd45-49db-815c-422f99c212ac" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_2d6b60a8-dd45-49db-815c-422f99c212ac_default" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2d6b60a8-dd45-49db-815c-422f99c212ac" xlink:to="loc_dei_EntityDomain_2d6b60a8-dd45-49db-815c-422f99c212ac_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_c7ba1ecd-4388-4d0b-b177-e3b5dbde97e6" xlink:href="https://xbrl.sec.gov/dei/2025/dei-2025.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2d6b60a8-dd45-49db-815c-422f99c212ac" xlink:to="loc_dei_EntityDomain_c7ba1ecd-4388-4d0b-b177-e3b5dbde97e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodInternationalAdvisorsIncMember_173e2da8-4cb9-465c-b136-2d8c60c0db7c" xlink:href="whg-20250630.xsd#whg_WestwoodInternationalAdvisorsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_c7ba1ecd-4388-4d0b-b177-e3b5dbde97e6" xlink:to="loc_whg_WestwoodInternationalAdvisorsIncMember_173e2da8-4cb9-465c-b136-2d8c60c0db7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_04213d4a-b20c-4972-8a30-5539b2d9931d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_04213d4a-b20c-4972-8a30-5539b2d9931d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_04213d4a-b20c-4972-8a30-5539b2d9931d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_04213d4a-b20c-4972-8a30-5539b2d9931d" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_04213d4a-b20c-4972-8a30-5539b2d9931d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_ccd3a7a5-90fe-460a-918b-1bd44e7aaf61" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_04213d4a-b20c-4972-8a30-5539b2d9931d" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_ccd3a7a5-90fe-460a-918b-1bd44e7aaf61" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_6e890141-371d-45a7-a602-737a3683247f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MutualFundMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_ccd3a7a5-90fe-460a-918b-1bd44e7aaf61" xlink:to="loc_us-gaap_MutualFundMember_6e890141-371d-45a7-a602-737a3683247f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_178c1944-1baa-40dc-939a-9b8ad24c7114" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_420cfab2-f0fb-4455-88eb-9f56fde03a2c" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_178c1944-1baa-40dc-939a-9b8ad24c7114" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_178c1944-1baa-40dc-939a-9b8ad24c7114_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_178c1944-1baa-40dc-939a-9b8ad24c7114" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_178c1944-1baa-40dc-939a-9b8ad24c7114_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_acb29457-c561-42ee-948d-a3e0a81d2ffc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_178c1944-1baa-40dc-939a-9b8ad24c7114" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_acb29457-c561-42ee-948d-a3e0a81d2ffc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_2a422468-40dd-400a-bb53-5c53c64f3ca7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AntidilutiveSecuritiesNameDomain_acb29457-c561-42ee-948d-a3e0a81d2ffc" xlink:to="loc_us-gaap_RestrictedStockMember_2a422468-40dd-400a-bb53-5c53c64f3ca7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_9645191b-7256-496c-9563-8e04b48d403e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_9645191b-7256-496c-9563-8e04b48d403e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_6758c9eb-0ad3-4580-a667-278e8f293011" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_6758c9eb-0ad3-4580-a667-278e8f293011" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal_f342c60f-26ea-4d89-94cf-b74b9db27a24" xlink:href="whg-20250630.xsd#whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal_f342c60f-26ea-4d89-94cf-b74b9db27a24" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_FundPurchasesOfCommonStock_71a63088-b800-4116-b65a-52f5e4e72a66" xlink:href="whg-20250630.xsd#whg_FundPurchasesOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_whg_FundPurchasesOfCommonStock_71a63088-b800-4116-b65a-52f5e4e72a66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant_c2795cac-37d0-45da-9564-ea9a12b72009" xlink:href="whg-20250630.xsd#whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant_c2795cac-37d0-45da-9564-ea9a12b72009" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_447c4781-e2cb-4085-88c0-0b4684b3f380" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_SharePrice_447c4781-e2cb-4085-88c0-0b4684b3f380" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_3c0458f8-4beb-4773-b9f4-064532d54b01" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsForRepurchaseOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_3c0458f8-4beb-4773-b9f4-064532d54b01" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_f1e682c9-e691-42d7-8d47-51d8f47ea3f4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_f1e682c9-e691-42d7-8d47-51d8f47ea3f4" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_8f850f47-d55d-4766-b734-563914c6c24b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_8f850f47-d55d-4766-b734-563914c6c24b" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_17fee6b9-6fce-49ec-8e2d-b2a8ca8f8c37" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_17fee6b9-6fce-49ec-8e2d-b2a8ca8f8c37" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_7b5a3362-8a19-405e-95e3-528903f23944" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_7b5a3362-8a19-405e-95e3-528903f23944" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_975d8ed3-3b88-4b77-b964-1b26f40a6d8f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_975d8ed3-3b88-4b77-b964-1b26f40a6d8f" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_b88a8360-a981-4fb0-b9d5-3c0524e05d8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_b88a8360-a981-4fb0-b9d5-3c0524e05d8a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundIncentiveAwardLiability_1c32ae69-6a02-4103-94c4-d9dda0c4ffab" xlink:href="whg-20250630.xsd#whg_MutualFundIncentiveAwardLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_whg_MutualFundIncentiveAwardLiability_1c32ae69-6a02-4103-94c4-d9dda0c4ffab" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_0bede2a6-05cd-4929-9d87-b8e94493e468" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_0bede2a6-05cd-4929-9d87-b8e94493e468" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockAwardForfeitures_6c4d48ac-fa62-4b7f-9a36-5a8a209a5734" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockAwardForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_RestrictedStockAwardForfeitures_6c4d48ac-fa62-4b7f-9a36-5a8a209a5734" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_afa9d696-773c-4485-8deb-c7747fdd7f7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_afa9d696-773c-4485-8deb-c7747fdd7f7a" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_d0329ee9-341d-474e-8fe3-6f97d170982c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_d0329ee9-341d-474e-8fe3-6f97d170982c" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_1b3c78a8-496c-450b-a7d2-6201f8935ea4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0c36f339-b2c1-4718-b011-0d7a41b95600" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_1b3c78a8-496c-450b-a7d2-6201f8935ea4" xlink:type="arc" order="18"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#LONGTERMINCENTIVECOMPENSATIONDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_be4609fe-beb5-4381-ba32-c83f89ac68dd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8b386a64-68ce-4d7d-9db2-e5dc4acac451" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_be4609fe-beb5-4381-ba32-c83f89ac68dd" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8b386a64-68ce-4d7d-9db2-e5dc4acac451" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_ca22834f-962b-4c5c-9305-7b769f830e9f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8b386a64-68ce-4d7d-9db2-e5dc4acac451" xlink:to="loc_us-gaap_AwardTypeAxis_ca22834f-962b-4c5c-9305-7b769f830e9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ca22834f-962b-4c5c-9305-7b769f830e9f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_ca22834f-962b-4c5c-9305-7b769f830e9f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ca22834f-962b-4c5c-9305-7b769f830e9f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_ca22834f-962b-4c5c-9305-7b769f830e9f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DomesticEmployeeServiceAwardMember_1f517d9c-9541-45ff-8c11-c74f35889c91" xlink:href="whg-20250630.xsd#whg_DomesticEmployeeServiceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:to="loc_whg_DomesticEmployeeServiceAwardMember_1f517d9c-9541-45ff-8c11-c74f35889c91" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_8e49c84a-87a9-445f-ab70-482b7657fc7a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:to="loc_us-gaap_PerformanceSharesMember_8e49c84a-87a9-445f-ab70-482b7657fc7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DomesticServiceAndPerformanceAwardMember_23c3f37a-f9af-4189-b38b-c433139382e9" xlink:href="whg-20250630.xsd#whg_DomesticServiceAndPerformanceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:to="loc_whg_DomesticServiceAndPerformanceAwardMember_23c3f37a-f9af-4189-b38b-c433139382e9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CanadianEmployeeServiceAwardMember_2e56030e-3122-4b17-b7a6-afc06cc225c0" xlink:href="whg-20250630.xsd#whg_CanadianEmployeeServiceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:to="loc_whg_CanadianEmployeeServiceAwardMember_2e56030e-3122-4b17-b7a6-afc06cc225c0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_56b907fd-fcaa-417c-b0ea-a0c0bd7157ef" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9245298b-d6e4-4cc8-981d-2996175266ae" xlink:to="loc_us-gaap_RestrictedStockMember_56b907fd-fcaa-417c-b0ea-a0c0bd7157ef" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_1d00a841-4509-48c4-ad70-faf5f8d9cf88" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8b386a64-68ce-4d7d-9db2-e5dc4acac451" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_1d00a841-4509-48c4-ad70-faf5f8d9cf88" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_1d00a841-4509-48c4-ad70-faf5f8d9cf88_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1d00a841-4509-48c4-ad70-faf5f8d9cf88" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_1d00a841-4509-48c4-ad70-faf5f8d9cf88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_845bc012-a5dd-46e9-8cc4-c4bd3a4cd2cd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_1d00a841-4509-48c4-ad70-faf5f8d9cf88" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_845bc012-a5dd-46e9-8cc4-c4bd3a4cd2cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_cb338f5a-e026-45ad-96b7-bb845e69b6f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_8b386a64-68ce-4d7d-9db2-e5dc4acac451" xlink:to="loc_us-gaap_PlanNameAxis_cb338f5a-e026-45ad-96b7-bb845e69b6f9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_cb338f5a-e026-45ad-96b7-bb845e69b6f9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_cb338f5a-e026-45ad-96b7-bb845e69b6f9" xlink:to="loc_us-gaap_PlanNameDomain_cb338f5a-e026-45ad-96b7-bb845e69b6f9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_61c87361-260e-4b71-abbf-0c3f7566ae3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_cb338f5a-e026-45ad-96b7-bb845e69b6f9" xlink:to="loc_us-gaap_PlanNameDomain_61c87361-260e-4b71-abbf-0c3f7566ae3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_efc12138-32f1-4b4f-9f39-3df559d92b24" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_be4609fe-beb5-4381-ba32-c83f89ac68dd" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_efc12138-32f1-4b4f-9f39-3df559d92b24" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails1" xlink:type="simple" xlink:href="whg-20250630.xsd#LONGTERMINCENTIVECOMPENSATIONDetails1"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_67c3ebf7-a29b-4dd3-9bd8-d63d3144f1f9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d3808fbd-cbfa-41dd-b12c-e43da321adaf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_67c3ebf7-a29b-4dd3-9bd8-d63d3144f1f9" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d3808fbd-cbfa-41dd-b12c-e43da321adaf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9aba90ac-441a-470d-99fb-682520991536" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_d3808fbd-cbfa-41dd-b12c-e43da321adaf" xlink:to="loc_us-gaap_AwardTypeAxis_9aba90ac-441a-470d-99fb-682520991536" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aba90ac-441a-470d-99fb-682520991536_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9aba90ac-441a-470d-99fb-682520991536" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9aba90ac-441a-470d-99fb-682520991536_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a23eb0ce-bbdc-4178-afd8-6a028c083879" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9aba90ac-441a-470d-99fb-682520991536" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a23eb0ce-bbdc-4178-afd8-6a028c083879" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_9b2bf7a8-73e1-44fe-92a9-9809ddbf11ea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_a23eb0ce-bbdc-4178-afd8-6a028c083879" xlink:to="loc_us-gaap_RestrictedStockMember_9b2bf7a8-73e1-44fe-92a9-9809ddbf11ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_67c3ebf7-a29b-4dd3-9bd8-d63d3144f1f9" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_d79d88ed-8493-42df-9881-190eee7e6e4c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_d79d88ed-8493-42df-9881-190eee7e6e4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_4b3e1a1e-0981-4f1a-bc54-0968b9205e97" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_4b3e1a1e-0981-4f1a-bc54-0968b9205e97" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0ed95c18-1621-4550-bbf8-ffbe459d2f74" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_0ed95c18-1621-4550-bbf8-ffbe459d2f74" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_3d80ce8e-24bc-4efb-8beb-afa0dd349b73" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_3d80ce8e-24bc-4efb-8beb-afa0dd349b73" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_8fe8c85d-38e2-416c-8db1-69f6a38c2686" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_fef79320-4e1b-406f-bbb9-d50d5475b54a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_fef79320-4e1b-406f-bbb9-d50d5475b54a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_131f3698-391f-4e25-baf6-98a87cb2db44" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_131f3698-391f-4e25-baf6-98a87cb2db44" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_c2b561e8-c9f9-44e7-a084-7fdb23c69e92" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_c2b561e8-c9f9-44e7-a084-7fdb23c69e92" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_5fbb6b59-5dc7-42f7-9ffe-d11e7097a6d0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_e80fe6f7-96a1-40ec-a209-9d60ca11ddf6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_5fbb6b59-5dc7-42f7-9ffe-d11e7097a6d0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_cdf567f8-ff6d-4972-b633-8b260f28a7bc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails2" xlink:type="simple" xlink:href="whg-20250630.xsd#LONGTERMINCENTIVECOMPENSATIONDetails2"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails2" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a1d5724d-cc19-4720-81e1-7bc3365f3710" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e8587e72-d1ad-443d-82ba-afd22f160dec" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a1d5724d-cc19-4720-81e1-7bc3365f3710" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e8587e72-d1ad-443d-82ba-afd22f160dec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_4422bb7d-82a0-4cc2-938a-79d54605f117" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_e8587e72-d1ad-443d-82ba-afd22f160dec" xlink:to="loc_us-gaap_AwardTypeAxis_4422bb7d-82a0-4cc2-938a-79d54605f117" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4422bb7d-82a0-4cc2-938a-79d54605f117_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_4422bb7d-82a0-4cc2-938a-79d54605f117" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_4422bb7d-82a0-4cc2-938a-79d54605f117_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_eb501021-7d06-4bd7-90bc-11a8a85d4f99" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_4422bb7d-82a0-4cc2-938a-79d54605f117" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_eb501021-7d06-4bd7-90bc-11a8a85d4f99" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_d5caf59e-d3b4-4561-a034-11fd42c9b562" xlink:href="whg-20250630.xsd#whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_eb501021-7d06-4bd7-90bc-11a8a85d4f99" xlink:to="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_d5caf59e-d3b4-4561-a034-11fd42c9b562" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_a1d5724d-cc19-4720-81e1-7bc3365f3710" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_a2337104-d2a4-4d69-afa3-a2aedf61c9f6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_a2337104-d2a4-4d69-afa3-a2aedf61c9f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_36d08aee-326e-455e-851f-a03cd508b5b4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_36d08aee-326e-455e-851f-a03cd508b5b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_78d2f368-4433-4736-9286-21f993a8530e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_78d2f368-4433-4736-9286-21f993a8530e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_6239ac89-8de1-40ec-9efc-7aa09a94da52" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_6239ac89-8de1-40ec-9efc-7aa09a94da52" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_f2328ad6-aeee-47ef-b222-a60b1e1213e0" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_36b5e92d-bde8-497d-9193-ae809f3c5a24" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_36b5e92d-bde8-497d-9193-ae809f3c5a24" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_a9ef2372-4fb7-492a-b401-203c8c178729" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_a9ef2372-4fb7-492a-b401-203c8c178729" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_05eaf779-b8ac-4228-a7ec-a6191835b6a5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_05eaf779-b8ac-4228-a7ec-a6191835b6a5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_20137b8c-159b-46c8-84e4-746042321f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f3acba70-fe3a-47e9-bdea-501a3e8116d7" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_20137b8c-159b-46c8-84e4-746042321f9d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_f7eec546-9500-4653-a865-28faad3c3655" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/RELATEDPARTYTRANSACTIONSDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#RELATEDPARTYTRANSACTIONSDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/RELATEDPARTYTRANSACTIONSDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_cc8d684f-4b7f-4e42-baf8-1c11fefcef59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_cc8d684f-4b7f-4e42-baf8-1c11fefcef59" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_feccb682-cf24-4e99-af0f-8c90a7039cb7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_cc8d684f-4b7f-4e42-baf8-1c11fefcef59" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_feccb682-cf24-4e99-af0f-8c90a7039cb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_feccb682-cf24-4e99-af0f-8c90a7039cb7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_feccb682-cf24-4e99-af0f-8c90a7039cb7" xlink:to="loc_us-gaap_RelatedPartyDomain_feccb682-cf24-4e99-af0f-8c90a7039cb7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_7b940a51-f7ec-49df-910d-87b1ed7f8bba" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_feccb682-cf24-4e99-af0f-8c90a7039cb7" xlink:to="loc_us-gaap_RelatedPartyDomain_7b940a51-f7ec-49df-910d-87b1ed7f8bba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrustForBenefitOfEmployeesMember_15daeac6-f1e8-4918-991e-f430804d0b6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_TrustForBenefitOfEmployeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_7b940a51-f7ec-49df-910d-87b1ed7f8bba" xlink:to="loc_us-gaap_TrustForBenefitOfEmployeesMember_15daeac6-f1e8-4918-991e-f430804d0b6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_f3f0297d-431d-4e58-b81a-78a0bd72760c" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_cc8d684f-4b7f-4e42-baf8-1c11fefcef59" xlink:to="loc_srt_ConsolidatedEntitiesAxis_f3f0297d-431d-4e58-b81a-78a0bd72760c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_f3f0297d-431d-4e58-b81a-78a0bd72760c_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_f3f0297d-431d-4e58-b81a-78a0bd72760c" xlink:to="loc_srt_ConsolidatedEntitiesDomain_f3f0297d-431d-4e58-b81a-78a0bd72760c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_6ed4878a-0ebc-46a5-962e-b79b272376a6" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_f3f0297d-431d-4e58-b81a-78a0bd72760c" xlink:to="loc_srt_ConsolidatedEntitiesDomain_6ed4878a-0ebc-46a5-962e-b79b272376a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_40719bf4-2df0-49c4-ab96-872fa5335347" xlink:href="whg-20250630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_6ed4878a-0ebc-46a5-962e-b79b272376a6" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_40719bf4-2df0-49c4-ab96-872fa5335347" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_e84f36de-8e29-4afc-82d4-aad225235968" xlink:href="whg-20250630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_6ed4878a-0ebc-46a5-962e-b79b272376a6" xlink:to="loc_whg_PrivateEquityInvestmentsMember_e84f36de-8e29-4afc-82d4-aad225235968" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueFromRelatedParties_3529b211-ce25-43dd-8a92-1ecac5fb4b3f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DueFromRelatedParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:to="loc_us-gaap_DueFromRelatedParties_3529b211-ce25-43dd-8a92-1ecac5fb4b3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromRelatedParties_4e5fa295-5ef0-40d8-aec5-f7c7bb3a5344" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromRelatedParties"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:to="loc_us-gaap_RevenueFromRelatedParties_4e5fa295-5ef0-40d8-aec5-f7c7bb3a5344" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableRelatedPartiesCurrent_50e61db7-1667-4b02-81fa-729347ecf235" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableRelatedPartiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:to="loc_us-gaap_AccountsReceivableRelatedPartiesCurrent_50e61db7-1667-4b02-81fa-729347ecf235" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_f90429d3-2f0b-4fa9-a83b-d6ba97b7493d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_f0e2fa4a-72c3-4a82-9bc7-b0d2b19fb33a" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_f90429d3-2f0b-4fa9-a83b-d6ba97b7493d" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LEASESTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#LEASESTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/LEASESTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeLeaseDescriptionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_ce6cafa7-07c7-4b27-a02a-68edc4e80286" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_CounterpartyNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:to="loc_srt_CounterpartyNameAxis_ce6cafa7-07c7-4b27-a02a-68edc4e80286" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ce6cafa7-07c7-4b27-a02a-68edc4e80286_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_CounterpartyNameAxis_ce6cafa7-07c7-4b27-a02a-68edc4e80286" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_ce6cafa7-07c7-4b27-a02a-68edc4e80286_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_3ea1a8a8-727b-4407-bee7-f66e4a34e9b3" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_RepurchaseAgreementCounterpartyNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_CounterpartyNameAxis_ce6cafa7-07c7-4b27-a02a-68edc4e80286" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_3ea1a8a8-727b-4407-bee7-f66e4a34e9b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_21683478-0e1d-4618-9338-e42adff77708" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_21683478-0e1d-4618-9338-e42adff77708" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_21683478-0e1d-4618-9338-e42adff77708_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_21683478-0e1d-4618-9338-e42adff77708" xlink:to="loc_us-gaap_SegmentDomain_21683478-0e1d-4618-9338-e42adff77708_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_e8ffff96-e7b5-453e-b5a4-36b1a507404d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_21683478-0e1d-4618-9338-e42adff77708" xlink:to="loc_us-gaap_SegmentDomain_e8ffff96-e7b5-453e-b5a4-36b1a507404d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionAxis_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicDistributionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:to="loc_us-gaap_GeographicDistributionAxis_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicDistributionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_GeographicDistributionAxis_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3" xlink:to="loc_us-gaap_GeographicDistributionDomain_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_bc43ccbd-ae21-494e-9602-b88ed5e88759" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_GeographicDistributionDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_GeographicDistributionAxis_a77bf6bc-fa0f-4212-bae4-8f389ad82ab3" xlink:to="loc_us-gaap_GeographicDistributionDomain_bc43ccbd-ae21-494e-9602-b88ed5e88759" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_e4fda78f-17c7-49d2-a135-9335dcfe8d76" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_e4fda78f-17c7-49d2-a135-9335dcfe8d76" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e4fda78f-17c7-49d2-a135-9335dcfe8d76_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_e4fda78f-17c7-49d2-a135-9335dcfe8d76" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_e4fda78f-17c7-49d2-a135-9335dcfe8d76_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_ec0bc615-ed1a-4fa6-9623-7b2ae475ad9a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_e4fda78f-17c7-49d2-a135-9335dcfe8d76" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_ec0bc615-ed1a-4fa6-9623-7b2ae475ad9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermAxis_7218c7f7-48a0-443f-b9fb-270eee390ca9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LesseeLeaseDescriptionTable_c1b6c6e0-3c9e-43e7-a082-f0f4ca70e114" xlink:to="loc_us-gaap_LeaseContractualTermAxis_7218c7f7-48a0-443f-b9fb-270eee390ca9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_7218c7f7-48a0-443f-b9fb-270eee390ca9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LeaseContractualTermAxis_7218c7f7-48a0-443f-b9fb-270eee390ca9" xlink:to="loc_us-gaap_LeaseContractualTermDomain_7218c7f7-48a0-443f-b9fb-270eee390ca9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_b1d4485a-923f-4c02-bcf8-d662ea4fad6f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LeaseContractualTermDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LeaseContractualTermAxis_7218c7f7-48a0-443f-b9fb-270eee390ca9" xlink:to="loc_us-gaap_LeaseContractualTermDomain_b1d4485a-923f-4c02-bcf8-d662ea4fad6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_924aca56-5ddd-4762-b5eb-69cd905ea808" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubleaseIncome"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_SubleaseIncome_924aca56-5ddd-4762-b5eb-69cd905ea808" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_978505d1-7254-4cb4-9d6a-87322a9e33fb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingLeaseRightOfUseAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_978505d1-7254-4cb4-9d6a-87322a9e33fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_3238ae9b-00dd-4eab-a7b4-e551fcdfe977" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_3238ae9b-00dd-4eab-a7b4-e551fcdfe977" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalLeaseObligationsIncurred_ee4c1a04-bda3-4fa7-a1ef-a720a2519e10" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CapitalLeaseObligationsIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_CapitalLeaseObligationsIncurred_ee4c1a04-bda3-4fa7-a1ef-a720a2519e10" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LeaseSquareFootage_171a5282-ebed-4bd2-899c-20a300e86d06" xlink:href="whg-20250630.xsd#whg_LeaseSquareFootage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_whg_LeaseSquareFootage_171a5282-ebed-4bd2-899c-20a300e86d06" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Corporateofficesremainingleaseterms_3fdc0184-75bb-40ce-968c-83e33cf0533b" xlink:href="whg-20250630.xsd#whg_Corporateofficesremainingleaseterms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_whg_Corporateofficesremainingleaseterms_3fdc0184-75bb-40ce-968c-83e33cf0533b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_d3df2f2b-72a9-4d1d-9e48-5824f917b498" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LesseeOperatingLeaseTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_d3df2f2b-72a9-4d1d-9e48-5824f917b498" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandSubjectToGroundLeases_83f17229-9f91-4004-a2ab-0d290537d133" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LandSubjectToGroundLeases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_4b0f0816-c5e3-4b07-82b1-f8dc87e8315d" xlink:to="loc_us-gaap_LandSubjectToGroundLeases_83f17229-9f91-4004-a2ab-0d290537d133" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SEGMENTREPORTINGDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#SEGMENTREPORTINGDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/SEGMENTREPORTINGDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6307d3c6-6b99-4ff6-a618-5f0f823dd21e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6307d3c6-6b99-4ff6-a618-5f0f823dd21e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_9ae140ab-4215-49b8-b6fd-36c518839efb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6307d3c6-6b99-4ff6-a618-5f0f823dd21e" xlink:to="loc_us-gaap_AwardTypeAxis_9ae140ab-4215-49b8-b6fd-36c518839efb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9ae140ab-4215-49b8-b6fd-36c518839efb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_9ae140ab-4215-49b8-b6fd-36c518839efb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_9ae140ab-4215-49b8-b6fd-36c518839efb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_acdf8a01-d425-4614-98be-75216a8ab7fc" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_9ae140ab-4215-49b8-b6fd-36c518839efb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_acdf8a01-d425-4614-98be-75216a8ab7fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_820b7b35-bd61-4d2d-9d25-a12d6c81ea33" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_acdf8a01-d425-4614-98be-75216a8ab7fc" xlink:to="loc_us-gaap_RestrictedStockMember_820b7b35-bd61-4d2d-9d25-a12d6c81ea33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_7e894b3a-3a4c-4dc1-8a66-0004a0858d52" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6307d3c6-6b99-4ff6-a618-5f0f823dd21e" xlink:to="loc_srt_ConsolidationItemsAxis_7e894b3a-3a4c-4dc1-8a66-0004a0858d52" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_7e894b3a-3a4c-4dc1-8a66-0004a0858d52_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_7e894b3a-3a4c-4dc1-8a66-0004a0858d52" xlink:to="loc_srt_ConsolidationItemsDomain_7e894b3a-3a4c-4dc1-8a66-0004a0858d52_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_23bd13f0-0bec-43e7-b7f7-98766187540e" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_7e894b3a-3a4c-4dc1-8a66-0004a0858d52" xlink:to="loc_srt_ConsolidationItemsDomain_23bd13f0-0bec-43e7-b7f7-98766187540e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_dc902778-c40f-411e-a886-4c2f4da899e7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_23bd13f0-0bec-43e7-b7f7-98766187540e" xlink:to="loc_us-gaap_OperatingSegmentsMember_dc902778-c40f-411e-a886-4c2f4da899e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_d8b31126-1b6f-49bf-b3bf-2d98f072ecab" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_23bd13f0-0bec-43e7-b7f7-98766187540e" xlink:to="loc_us-gaap_CorporateNonSegmentMember_d8b31126-1b6f-49bf-b3bf-2d98f072ecab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_ba5d2ce1-8566-4be8-b10a-4497ee135eb6" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_23bd13f0-0bec-43e7-b7f7-98766187540e" xlink:to="loc_us-gaap_IntersegmentEliminationMember_ba5d2ce1-8566-4be8-b10a-4497ee135eb6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_6307d3c6-6b99-4ff6-a618-5f0f823dd21e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8" xlink:to="loc_us-gaap_SegmentDomain_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_c40b0e1e-9b3c-483b-96c1-b79ee9b34dc8" xlink:to="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisoryMember_8b000254-b838-498d-a04c-ffe8f5aead63" xlink:href="whg-20250630.xsd#whg_AdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:to="loc_whg_AdvisoryMember_8b000254-b838-498d-a04c-ffe8f5aead63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustMember_5651e9e9-b346-4d4f-8ed0-b9701828237c" xlink:href="whg-20250630.xsd#whg_TrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:to="loc_whg_TrustMember_5651e9e9-b346-4d4f-8ed0-b9701828237c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_33da96bd-3144-4150-8377-f2f14dd62221" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CorporateNonSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:to="loc_us-gaap_CorporateNonSegmentMember_33da96bd-3144-4150-8377-f2f14dd62221" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_1f82586b-2d19-4420-981d-450ce8e5dbaa" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ebe27652-c107-43b9-8573-1c84eca37242" xlink:to="loc_us-gaap_IntersegmentEliminationMember_1f82586b-2d19-4420-981d-450ce8e5dbaa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RevenueFromExternalSources_9d8a1e67-623e-4136-a674-5eb15319f870" xlink:href="whg-20250630.xsd#whg_RevenueFromExternalSources"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_whg_RevenueFromExternalSources_9d8a1e67-623e-4136-a674-5eb15319f870" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_NetIntersegmentRevenues_cf5d893c-346f-4e4f-998a-ea8aff9bc140" xlink:href="whg-20250630.xsd#whg_NetIntersegmentRevenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_whg_NetIntersegmentRevenues_cf5d893c-346f-4e4f-998a-ea8aff9bc140" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNet_4d7b512a-294a-4f5f-a21e-45315716968c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentIncomeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_InvestmentIncomeNet_4d7b512a-294a-4f5f-a21e-45315716968c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Otherrevenue_18cf1ba8-1fc5-46b2-9edf-7ea77d81aaeb" xlink:href="whg-20250630.xsd#whg_Otherrevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_whg_Otherrevenue_18cf1ba8-1fc5-46b2-9edf-7ea77d81aaeb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_92761e26-a63e-4afa-860f-606082e2d7b7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_Revenues_92761e26-a63e-4afa-860f-606082e2d7b7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_25f40a38-d861-429a-a2dc-e81e19612b8a" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_Assets_25f40a38-d861-429a-a2dc-e81e19612b8a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_c5dd2384-161d-43f3-bbf9-da218a595cbf" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_Goodwill_c5dd2384-161d-43f3-bbf9-da218a595cbf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_090f2d80-62db-405c-b416-41d2efcef68b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_EquityMethodInvestments_090f2d80-62db-405c-b416-41d2efcef68b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_5e6c504f-c4e4-4a45-8c01-4caee317bc83" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_5e6c504f-c4e4-4a45-8c01-4caee317bc83" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeInterestEarningAsset_48efea96-9ed4-4159-bc54-f5b49ea407ca" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InterestIncomeInterestEarningAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_InterestIncomeInterestEarningAsset_48efea96-9ed4-4159-bc54-f5b49ea407ca" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_5080b1f3-dfc2-4f46-8525-dcd3470a1c67" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_1c6c9a6b-96a1-4bc7-9033-efd235e51bd5" xlink:to="loc_us-gaap_NetIncomeLoss_5080b1f3-dfc2-4f46-8525-dcd3470a1c67" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SUBSEQUENTEVENTSDetailsTextual" xlink:type="simple" xlink:href="whg-20250630.xsd#SUBSEQUENTEVENTSDetailsTextual"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/SUBSEQUENTEVENTSDetailsTextual" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTable_2ca924e9-47b5-4179-8bc9-0be58becfc0c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_SubsequentEventTable_2ca924e9-47b5-4179-8bc9-0be58becfc0c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2ca924e9-47b5-4179-8bc9-0be58becfc0c" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_4774a769-e18b-47ec-8ada-691acdae8312" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_a37eb7ba-c4e2-46b0-8b1b-aeb3b9d0bc2b" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_4774a769-e18b-47ec-8ada-691acdae8312" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_fdb26811-e70a-4a4c-b733-82fadd832ee4" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_4774a769-e18b-47ec-8ada-691acdae8312" xlink:to="loc_us-gaap_SubsequentEventMember_fdb26811-e70a-4a4c-b733-82fadd832ee4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_e9f7ce4d-6124-4570-8c24-7606c4593f35" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_SubsequentEventTable_2ca924e9-47b5-4179-8bc9-0be58becfc0c" xlink:to="loc_srt_ProductOrServiceAxis_e9f7ce4d-6124-4570-8c24-7606c4593f35" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_e9f7ce4d-6124-4570-8c24-7606c4593f35_default" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_e9f7ce4d-6124-4570-8c24-7606c4593f35" xlink:to="loc_srt_ProductsAndServicesDomain_e9f7ce4d-6124-4570-8c24-7606c4593f35_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_4a58badd-19b9-4131-bbd7-393bc4736514" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_e9f7ce4d-6124-4570-8c24-7606c4593f35" xlink:to="loc_srt_ProductsAndServicesDomain_4a58badd-19b9-4131-bbd7-393bc4736514" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedFeesMember_2986e5b8-a16f-4d2c-9a09-c4b0d427c458" xlink:href="whg-20250630.xsd#whg_TrustPerformanceBasedFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_4a58badd-19b9-4131-bbd7-393bc4736514" xlink:to="loc_whg_TrustPerformanceBasedFeesMember_2986e5b8-a16f-4d2c-9a09-c4b0d427c458" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_46cd4a53-35a3-4626-a95f-d8bd97e4d3a8" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_CommonStockDividendsPerShareDeclared"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_46cd4a53-35a3-4626-a95f-d8bd97e4d3a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_a4662c28-3a1f-48cb-8b44-060d2cbfcf86" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendPayableDateToBePaidDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_a4662c28-3a1f-48cb-8b44-060d2cbfcf86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_99dffc70-ccd0-4201-9bd2-09d6b6930293" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_DividendsPayableDateOfRecordDayMonthAndYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_99dffc70-ccd0-4201-9bd2-09d6b6930293" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_48c3b052-05f4-4e8a-8308-63af79a441d9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_48c3b052-05f4-4e8a-8308-63af79a441d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_f1d90bbb-79a6-42d5-8eda-e9f6f2875dcb" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchasedDuringPeriodValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_f1d90bbb-79a6-42d5-8eda-e9f6f2875dcb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_46f8a925-edcd-4368-b1fa-3a6202847550" xlink:href="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd#srt_StockRepurchaseProgramAuthorizedAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_46f8a925-edcd-4368-b1fa-3a6202847550" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_ad8eadfa-41a4-4f7f-9f92-6ac08dc2bd59" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_ad8eadfa-41a4-4f7f-9f92-6ac08dc2bd59" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_StockRepurchaseProgram_2456480f-35ae-438b-9584-33821adfa423" xlink:href="whg-20250630.xsd#whg_StockRepurchaseProgram"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_whg_StockRepurchaseProgram_2456480f-35ae-438b-9584-33821adfa423" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_StockRepurchaseAuthorizationSubsequentEvent_81fd0ad6-0f86-4b7f-af9e-ce0803929846" xlink:href="whg-20250630.xsd#whg_StockRepurchaseAuthorizationSubsequentEvent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_whg_StockRepurchaseAuthorizationSubsequentEvent_81fd0ad6-0f86-4b7f-af9e-ce0803929846" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventDescription_28628dc4-85e3-484b-8918-c8e1613ad03d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SubsequentEventDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_SubsequentEventDescription_28628dc4-85e3-484b-8918-c8e1613ad03d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_90fa1146-96d0-44fa-aa15-12704c06239b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_90fa1146-96d0-44fa-aa15-12704c06239b" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_3f97d196-a51c-4428-bfbc-30d6c3840e8d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentsAllOtherInvestmentsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_3f97d196-a51c-4428-bfbc-30d6c3840e8d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestInJointVentures_922f2a98-3525-49c2-8d9e-b03b101dfbc9" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestInJointVentures"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_f668ba48-3c30-4ce8-8ed3-3555219b19fd" xlink:to="loc_us-gaap_MinorityInterestInJointVentures_922f2a98-3525-49c2-8d9e-b03b101dfbc9" xlink:type="arc" order="12"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/BusinessCombinationsandAssetAcquisitionsDetails" xlink:type="simple" xlink:href="whg-20250630.xsd#BusinessCombinationsandAssetAcquisitionsDetails"/>
  <link:definitionLink xlink:role="http://westwoodgroup.com/role/BusinessCombinationsandAssetAcquisitionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionTable_5d6cdf3f-5428-4d9f-822c-2c82b346e88c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AssetAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_AssetAcquisitionTable_5d6cdf3f-5428-4d9f-822c-2c82b346e88c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueByAssetClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AssetAcquisitionTable_5d6cdf3f-5428-4d9f-822c-2c82b346e88c" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByAssetClassAxis_4dfbee6f-2d8d-4ef0-8152-3ca208d43ae2" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_2a642339-5a69-4414-b734-ee205abcaef2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_2a642339-5a69-4414-b734-ee205abcaef2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_fc24ae6b-a5e4-4aed-899d-a9e257e27874" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_AccountsReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:to="loc_us-gaap_AccountsReceivableMember_fc24ae6b-a5e4-4aed-899d-a9e257e27874" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember_b1228ad8-9101-4b3e-a4f8-3fbe91154887" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PropertyPlantAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentMember_b1228ad8-9101-4b3e-a4f8-3fbe91154887" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_3e8b5358-d107-47ff-8f0c-9fd2a1385075" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_OtherAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_b4eff16c-6918-4bc5-a689-dd3182a9f17b" xlink:to="loc_us-gaap_OtherAssetsMember_3e8b5358-d107-47ff-8f0c-9fd2a1385075" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_67c199fd-a569-4cb0-9c0c-d774ac3bcf65" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_67c199fd-a569-4cb0-9c0c-d774ac3bcf65" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_f880994e-0cc2-4421-8f65-fcca4efc6478" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_f880994e-0cc2-4421-8f65-fcca4efc6478" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_33c7ece1-399c-433d-91d5-e045eb89906c" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_33c7ece1-399c-433d-91d5-e045eb89906c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription_b4a5cd90-ee34-4060-95a5-81221f5a3a4e" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription_b4a5cd90-ee34-4060-95a5-81221f5a3a4e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_01066cfc-38d6-4466-a6fd-95947b930183" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_01066cfc-38d6-4466-a6fd-95947b930183" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_7bf0e683-6826-4005-84e6-45683fe4d889" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_7bf0e683-6826-4005-84e6-45683fe4d889" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest_d615bf43-5275-40e5-b0ad-89106e9c9d1a" xlink:href="whg-20250630.xsd#whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest_d615bf43-5275-40e5-b0ad-89106e9c9d1a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BusinessCombinationConsiderationTransferredForBroadmark_dc2ffd83-f4d1-4b2e-8445-f36b1125a553" xlink:href="whg-20250630.xsd#whg_BusinessCombinationConsiderationTransferredForBroadmark"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_whg_BusinessCombinationConsiderationTransferredForBroadmark_dc2ffd83-f4d1-4b2e-8445-f36b1125a553" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PaymentsToAcquireBroadmarkGross_064f556a-f784-4821-9673-cc9c8ebb5db6" xlink:href="whg-20250630.xsd#whg_PaymentsToAcquireBroadmarkGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_whg_PaymentsToAcquireBroadmarkGross_064f556a-f784-4821-9673-cc9c8ebb5db6" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_b7385384-0102-4fd6-a797-94497102fea7" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_b7385384-0102-4fd6-a797-94497102fea7" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_174b81b3-8b39-41de-bd71-1e3fc6fd3b7d" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_174b81b3-8b39-41de-bd71-1e3fc6fd3b7d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_15171526-77aa-49a0-8495-520a3853caea" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_15171526-77aa-49a0-8495-520a3853caea" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_3a010c21-d156-4925-a165-a5a05fbaf8a2" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_5c80aaf8-aa72-47fb-bbff-c41830393cac" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_3a010c21-d156-4925-a165-a5a05fbaf8a2" xlink:type="arc" order="12"/>
  </link:definitionLink>
</link:linkbase>
