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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019f3d68-ea05-741d-8168-5abfb7cfc814,g:c6356ca4-d17e-4b5f-b02d-2bbc9f0758b8-->
<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-20260630.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_019f3d68-eb5c-73de-b183-a546b9bf8911" 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_019f3d68-eb5c-72e4-ace6-93b093d2665e" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_StatementTable_019f3d68-eb5c-72e4-ace6-93b093d2665e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f3d68-eb5c-7177-9038-b980bf57207e" 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_019f3d68-eb5c-72e4-ace6-93b093d2665e" xlink:to="loc_srt_ProductOrServiceAxis_019f3d68-eb5c-7177-9038-b980bf57207e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5c-7177-9038-b980bf57207e_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_019f3d68-eb5c-7177-9038-b980bf57207e" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5c-7177-9038-b980bf57207e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" 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_019f3d68-eb5c-7177-9038-b980bf57207e" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetManagement1Member_019f3d68-eb5c-75af-8cac-3f2861273989" 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_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" xlink:to="loc_us-gaap_AssetManagement1Member_019f3d68-eb5c-75af-8cac-3f2861273989" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentPerformanceMember_019f3d68-eb5c-7acf-acc5-6dc270e4fda3" 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_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" xlink:to="loc_us-gaap_InvestmentPerformanceMember_019f3d68-eb5c-7acf-acc5-6dc270e4fda3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiduciaryAndTrustMember_019f3d68-eb5c-7dde-aefb-bcb2da77773d" 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_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" xlink:to="loc_us-gaap_FiduciaryAndTrustMember_019f3d68-eb5c-7dde-aefb-bcb2da77773d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedFeesMember_019f3d68-eb5c-7a8f-ab98-cb400a845517" xlink:href="whg-20260630.xsd#whg_TrustPerformanceBasedFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5c-7d18-828c-c466a0bbc9ff" xlink:to="loc_whg_TrustPerformanceBasedFeesMember_019f3d68-eb5c-7a8f-ab98-cb400a845517" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_019f3d68-eb5c-7d9a-9ca7-81c4bdede498" 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_019f3d68-eb5c-72e4-ace6-93b093d2665e" xlink:to="loc_srt_StatementScenarioAxis_019f3d68-eb5c-7d9a-9ca7-81c4bdede498" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019f3d68-eb5c-7d9a-9ca7-81c4bdede498_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_019f3d68-eb5c-7d9a-9ca7-81c4bdede498" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019f3d68-eb5c-7d9a-9ca7-81c4bdede498_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_019f3d68-eb5c-78ef-8610-eaeed6b3c7c1" 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_019f3d68-eb5c-7d9a-9ca7-81c4bdede498" xlink:to="loc_srt_ScenarioUnspecifiedDomain_019f3d68-eb5c-78ef-8610-eaeed6b3c7c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019f3d68-eb5c-7aac-b4bf-848745ce8c79" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019f3d68-eb5c-7aac-b4bf-848745ce8c79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillImpairmentLoss_019f3d68-eb5c-73b6-8100-e0769f66bb89" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_GoodwillImpairmentLoss_019f3d68-eb5c-73b6-8100-e0769f66bb89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_019f3d68-eb5c-7be0-aebd-362f77b11269" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_019f3d68-eb5c-7be0-aebd-362f77b11269" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019f3d68-eb5c-7859-965c-9d832ec91058" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_019f3d68-eb5c-7859-965c-9d832ec91058" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_019f3d68-eb5c-71b9-9aa2-c02fb62fcd42" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax_019f3d68-eb5c-71b9-9aa2-c02fb62fcd42" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019f3d68-eb5c-730e-b115-4ea6a0eb4e2f" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_019f3d68-eb5c-730e-b115-4ea6a0eb4e2f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_019f3d68-eb5c-7577-adae-a08b7ffab39c" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_GainLossOnInvestments_019f3d68-eb5c-7577-adae-a08b7ffab39c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestInNetIncomeLossOtherNoncontrollingInterestsNonredeemable_019f3d68-eb5c-7818-93b2-2faf469c4788" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_NoncontrollingInterestInNetIncomeLossOtherNoncontrollingInterestsNonredeemable_019f3d68-eb5c-7818-93b2-2faf469c4788" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_019f3d68-eb5c-7329-b1d2-1d7c69c68f04" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsExpensesAndLossesRecognized_019f3d68-eb5c-7329-b1d2-1d7c69c68f04" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTax_019f3d68-eb5c-7b93-8617-68f2c93bd824" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTax_019f3d68-eb5c-7b93-8617-68f2c93bd824" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_019f3d68-eb5c-7858-9252-8bd027714442" 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_019f3d68-eb5c-73de-b183-a546b9bf8911" xlink:to="loc_us-gaap_ProfitLoss_019f3d68-eb5c-7858-9252-8bd027714442" xlink:type="arc" order="10"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/CONDENSEDCONSOLIDATEDSTATEMENTOFSTOCKHOLDERSEQUITY" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5c-7dcf-b042-2314710fb971" 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_019f3d68-eb5c-7176-a050-f739b99133c6" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_StatementTable_019f3d68-eb5c-7176-a050-f739b99133c6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3" 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_019f3d68-eb5c-7176-a050-f739b99133c6" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3_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_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3" xlink:to="loc_us-gaap_EquityComponentDomain_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019f3d68-eb5c-7cad-a8d1-a12309afff12" 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_019f3d68-eb5c-74a9-9ec1-3fadcbbe7cd3" xlink:to="loc_us-gaap_EquityComponentDomain_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019f3d68-eb5c-7463-bf7e-8ec29d3d1811" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_CommonStockMember_019f3d68-eb5c-7463-bf7e-8ec29d3d1811" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019f3d68-eb5c-703e-93cb-fc7b79c0843c" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019f3d68-eb5c-703e-93cb-fc7b79c0843c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_019f3d68-eb5c-7174-93c0-43143203e01f" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_TreasuryStockMember_019f3d68-eb5c-7174-93c0-43143203e01f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f3d68-eb5c-783f-9567-7015b814be5b" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019f3d68-eb5c-783f-9567-7015b814be5b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019f3d68-eb5c-726e-a3c6-6b3f9e836701" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_RetainedEarningsMember_019f3d68-eb5c-726e-a3c6-6b3f9e836701" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_019f3d68-eb5c-7de2-92d0-6cfbec8fd0dc" 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_019f3d68-eb5c-7cad-a8d1-a12309afff12" xlink:to="loc_us-gaap_NoncontrollingInterestMember_019f3d68-eb5c-7de2-92d0-6cfbec8fd0dc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f3d68-eb5c-7e24-9947-f0f85569d303" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_StockholdersEquity_019f3d68-eb5c-7e24-9947-f0f85569d303" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019f3d68-eb5c-71fc-a740-4d9f0b3900c0" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019f3d68-eb5c-71fc-a740-4d9f0b3900c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f3d68-eb5c-79ff-884e-57f1d5a21cfa" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_NetIncomeLoss_019f3d68-eb5c-79ff-884e-57f1d5a21cfa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019f3d68-eb5c-700c-a85d-5d45f6c97c36" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_019f3d68-eb5c-700c-a85d-5d45f6c97c36" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f3d68-eb5c-7254-abf4-ed4fa8c3a7cd" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_019f3d68-eb5c-7254-abf4-ed4fa8c3a7cd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_019f3d68-eb5c-79ac-b7dc-b7ebbdb0640e" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationTax_019f3d68-eb5c-79ac-b7dc-b7ebbdb0640e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_019f3d68-eb5c-79ab-acd4-f997ca522952" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardNetOfForfeitures_019f3d68-eb5c-79ab-acd4-f997ca522952" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019f3d68-eb5c-710a-b5ce-4d8b221c7b7d" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_DividendsCommonStock_019f3d68-eb5c-710a-b5ce-4d8b221c7b7d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f3d68-eb5c-7e95-abdb-cc0b76dcf591" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019f3d68-eb5c-7e95-abdb-cc0b76dcf591" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockAwardForfeituresDividends_019f3d68-eb5c-7e21-bb63-da190ec85231" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_RestrictedStockAwardForfeituresDividends_019f3d68-eb5c-7e21-bb63-da190ec85231" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_019f3d68-eb5c-789e-b42d-fe8e3e97c727" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalOther_019f3d68-eb5c-789e-b42d-fe8e3e97c727" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_019f3d68-eb5c-7e22-b236-7aba041837aa" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_019f3d68-eb5c-7e22-b236-7aba041837aa" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TreasuryStockSharesAcquiredEmployeeStockPlan_019f3d68-eb5c-775b-b8e0-0eb87d7b96f4" xlink:href="whg-20260630.xsd#whg_TreasuryStockSharesAcquiredEmployeeStockPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_whg_TreasuryStockSharesAcquiredEmployeeStockPlan_019f3d68-eb5c-775b-b8e0-0eb87d7b96f4" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_019f3d68-eb5c-77c8-b1b6-362e1aabd537" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings_019f3d68-eb5c-77c8-b1b6-362e1aabd537" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019f3d68-eb5c-743a-9ed7-2da4c97abf49" 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_019f3d68-eb5c-7f3d-94c8-22774fdecfb1" 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_019f3d68-eb5c-7deb-9645-2b37fc9bd754" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_ProfitLoss_019f3d68-eb5c-7deb-9645-2b37fc9bd754" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f3d68-eb5c-73a4-97ce-20e162dbd7b0" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_019f3d68-eb5c-73a4-97ce-20e162dbd7b0" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_019f3d68-eb5c-74e5-93ff-de04b1e739ce" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_NoncontrollingInterestIncreaseFromBusinessCombination_019f3d68-eb5c-74e5-93ff-de04b1e739ce" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_019f3d68-eb5c-7335-b0bc-cd42e7958b49" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_RestrictedStockValueSharesIssuedNetOfTaxWithholdings_019f3d68-eb5c-7335-b0bc-cd42e7958b49" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f3d68-eb5c-70fc-89cc-e3234a312296" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_019f3d68-eb5c-70fc-89cc-e3234a312296" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019f3d68-eb5c-7321-b420-281af61ff44a" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardNetOfForfeitures_019f3d68-eb5c-7321-b420-281af61ff44a" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ReturnOfCapital_019f3d68-eb5c-700c-828e-c67014e95f62" xlink:href="whg-20260630.xsd#whg_ReturnOfCapital"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_whg_ReturnOfCapital_019f3d68-eb5c-700c-828e-c67014e95f62" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f3d68-eb5c-79a9-95a4-d46973a36d3e" 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_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_019f3d68-eb5c-79a9-95a4-d46973a36d3e" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan_019f3d68-eb5c-7ba3-8d36-30fb6b7e280b" xlink:href="whg-20260630.xsd#whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019f3d68-eb5c-7dcf-b042-2314710fb971" xlink:to="loc_whg_TreasuryStockValueAcquiredCostMethodEmployeeStockPlan_019f3d68-eb5c-7ba3-8d36-30fb6b7e280b" xlink:type="arc" order="24"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SUBSEQUENTEVENTS" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-75ae-8a56-d255ce3946f3" 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_019f3d68-eb5d-73e2-ae2d-11923bd3076b" 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_019f3d68-eb5d-75ae-8a56-d255ce3946f3" xlink:to="loc_us-gaap_SubsequentEventTable_019f3d68-eb5d-73e2-ae2d-11923bd3076b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019f3d68-eb5d-7c0d-8609-2472f3b55ec9" 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_019f3d68-eb5d-73e2-ae2d-11923bd3076b" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019f3d68-eb5d-7c0d-8609-2472f3b55ec9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7c0d-8609-2472f3b55ec9_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_019f3d68-eb5d-7c0d-8609-2472f3b55ec9" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7c0d-8609-2472f3b55ec9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7afd-b2da-3048291011ed" 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_019f3d68-eb5d-7c0d-8609-2472f3b55ec9" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7afd-b2da-3048291011ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019f3d68-eb5d-7248-97e8-1305a372ad9c" 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_019f3d68-eb5d-7afd-b2da-3048291011ed" xlink:to="loc_us-gaap_SubsequentEventMember_019f3d68-eb5d-7248-97e8-1305a372ad9c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONTables" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7eb7-8818-3d59ff63a263" 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_019f3d68-eb5d-7b8f-8bba-57df3b62758e" 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_019f3d68-eb5d-7eb7-8818-3d59ff63a263" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7b8f-8bba-57df3b62758e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7076-8f64-f3501e959d0c" 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_019f3d68-eb5d-7b8f-8bba-57df3b62758e" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7076-8f64-f3501e959d0c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7076-8f64-f3501e959d0c_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_019f3d68-eb5d-7076-8f64-f3501e959d0c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7076-8f64-f3501e959d0c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bb4-b3cc-936137bdae3c" 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_019f3d68-eb5d-7076-8f64-f3501e959d0c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bb4-b3cc-936137bdae3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectOnlyToServiceConditionMember_019f3d68-eb5d-7b6c-ba2d-ef9b7fbc5816" xlink:href="whg-20260630.xsd#whg_RestrictedStockSubjectOnlyToServiceConditionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bb4-b3cc-936137bdae3c" xlink:to="loc_whg_RestrictedStockSubjectOnlyToServiceConditionMember_019f3d68-eb5d-7b6c-ba2d-ef9b7fbc5816" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_019f3d68-eb5d-7fbc-8d83-9cf0993c84c1" xlink:href="whg-20260630.xsd#whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bb4-b3cc-936137bdae3c" xlink:to="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_019f3d68-eb5d-7fbc-8d83-9cf0993c84c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock_019f3d68-eb5d-777f-9dbb-4202573d6764" xlink:href="whg-20260630.xsd#whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7eb7-8818-3d59ff63a263" xlink:to="loc_whg_RestrictedStockSubjectOnlyToAServiceConditionPolicyTextBlock_019f3d68-eb5d-777f-9dbb-4202573d6764" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_019f3d68-eb5d-755e-813b-10738282d17d" 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_019f3d68-eb5d-7eb7-8818-3d59ff63a263" xlink:to="loc_us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_019f3d68-eb5d-755e-813b-10738282d17d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_019f3d68-eb5d-7b69-9242-ce3ad966a649" 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_019f3d68-eb5d-7eb7-8818-3d59ff63a263" xlink:to="loc_us-gaap_ScheduleOfSharebasedCompensationRestrictedStockAndRestrictedStockUnitsActivityTableTextBlock_019f3d68-eb5d-7b69-9242-ce3ad966a649" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock_019f3d68-eb5d-7e2d-82ee-dbff76272daa" xlink:href="whg-20260630.xsd#whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7eb7-8818-3d59ff63a263" xlink:to="loc_whg_RestrictedStockSubjectToServiceAndPerformanceConditionsPolicyTextBlock_019f3d68-eb5d-7e2d-82ee-dbff76272daa" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/EARNINGSPERSHAREDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5c-7509-bccc-6f9b6f06e20e" 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_019f3d68-eb5c-7087-aa28-160e274565ec" 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_019f3d68-eb5c-7509-bccc-6f9b6f06e20e" xlink:to="loc_us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_019f3d68-eb5c-7087-aa28-160e274565ec" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f3d68-eb5c-7e33-bc61-8e377ebbeea3" 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_019f3d68-eb5c-7087-aa28-160e274565ec" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f3d68-eb5c-7e33-bc61-8e377ebbeea3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5c-7e33-bc61-8e377ebbeea3_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_019f3d68-eb5c-7e33-bc61-8e377ebbeea3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5c-7e33-bc61-8e377ebbeea3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5c-70fe-862a-d8eea0c00724" 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_019f3d68-eb5c-7e33-bc61-8e377ebbeea3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5c-70fe-862a-d8eea0c00724" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5c-7a7a-bf32-a9463604938a" 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_019f3d68-eb5c-70fe-862a-d8eea0c00724" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5c-7a7a-bf32-a9463604938a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f3d68-eb5c-780f-a3be-cdc0a371a6e5" 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_019f3d68-eb5c-7509-bccc-6f9b6f06e20e" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f3d68-eb5c-780f-a3be-cdc0a371a6e5" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/INVESTMENTSDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" 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_019f3d68-eb5c-7120-bf2a-8d7e5efd8cdd" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesTable_019f3d68-eb5c-7120-bf2a-8d7e5efd8cdd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7a97-bb39-3df411f0acc2" 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_019f3d68-eb5c-7120-bf2a-8d7e5efd8cdd" xlink:to="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7a97-bb39-3df411f0acc2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7a97-bb39-3df411f0acc2_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_019f3d68-eb5c-7a97-bb39-3df411f0acc2" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7a97-bb39-3df411f0acc2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7189-8855-521e0aec4672" 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_019f3d68-eb5c-7a97-bb39-3df411f0acc2" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_019f3d68-eb5c-75db-9560-b453445b930c" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_019f3d68-eb5c-75db-9560-b453445b930c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsMember_019f3d68-eb5c-7370-9e08-79e6d0723378" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_MoneyMarketFundsMember_019f3d68-eb5c-7370-9e08-79e6d0723378" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityFundsMember_019f3d68-eb5c-7e92-bb39-e46723d6eb2c" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_EquityFundsMember_019f3d68-eb5c-7e92-bb39-e46723d6eb2c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesMember_019f3d68-eb5c-700e-bf97-ab058e936e45" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_EquitySecuritiesMember_019f3d68-eb5c-700e-bf97-ab058e936e45" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UsGaap_EquitySecuritiesMemberMember_019f3d68-eb5c-74d0-bfb4-3c17f32e6ff5" xlink:href="whg-20260630.xsd#whg_UsGaap_EquitySecuritiesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_whg_UsGaap_EquitySecuritiesMemberMember_019f3d68-eb5c-74d0-bfb4-3c17f32e6ff5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsMember_019f3d68-eb5c-798e-ae46-7a5eea327c57" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_PrivateEquityFundsMember_019f3d68-eb5c-798e-ae46-7a5eea327c57" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5c-72d2-8cb8-927614197bc1" xlink:href="whg-20260630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5c-72d2-8cb8-927614197bc1" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExchangeTradedFundsMember_019f3d68-eb5c-7b45-9ccc-ce1e0f03861c" 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_019f3d68-eb5c-7189-8855-521e0aec4672" xlink:to="loc_us-gaap_ExchangeTradedFundsMember_019f3d68-eb5c-7b45-9ccc-ce1e0f03861c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019f3d68-eb5c-76b5-8309-0675702c2159" 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_019f3d68-eb5c-7120-bf2a-8d7e5efd8cdd" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_019f3d68-eb5c-76b5-8309-0675702c2159" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-76b5-8309-0675702c2159_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_019f3d68-eb5c-76b5-8309-0675702c2159" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-76b5-8309-0675702c2159_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" 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_019f3d68-eb5c-76b5-8309-0675702c2159" xlink:to="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ZarvonaEnergyFundGPLPDomain_019f3d68-eb5c-70e9-a9f6-65924cf6ab0a" xlink:href="whg-20260630.xsd#whg_ZarvonaEnergyFundGPLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_ZarvonaEnergyFundGPLPDomain_019f3d68-eb5c-70e9-a9f6-65924cf6ab0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ZarvonaEnergyFundIIALPDomain_019f3d68-eb5c-7e0f-be4f-465005aef969" xlink:href="whg-20260630.xsd#whg_ZarvonaEnergyFundIIALPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_ZarvonaEnergyFundIIALPDomain_019f3d68-eb5c-7e0f-be4f-465005aef969" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BroadmarkAssetManagementLLCDomain_019f3d68-eb5c-7662-b0be-9527c46e4436" xlink:href="whg-20260630.xsd#whg_BroadmarkAssetManagementLLCDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_BroadmarkAssetManagementLLCDomain_019f3d68-eb5c-7662-b0be-9527c46e4436" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_SalientMLPTotalReturnFundLPDomain_019f3d68-eb5c-78d9-9aea-8edacd1c7afc" xlink:href="whg-20260630.xsd#whg_SalientMLPTotalReturnFundLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_SalientMLPTotalReturnFundLPDomain_019f3d68-eb5c-78d9-9aea-8edacd1c7afc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_SalientMLPTotalReturnTEFundLPDomain_019f3d68-eb5c-72e6-b781-1355644692b8" xlink:href="whg-20260630.xsd#whg_SalientMLPTotalReturnTEFundLPDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_SalientMLPTotalReturnTEFundLPDomain_019f3d68-eb5c-72e6-b781-1355644692b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalMember_019f3d68-eb5c-72d4-8338-ef28dc707f9c" xlink:href="whg-20260630.xsd#whg_TotalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityInterestIssuedOrIssuableTypeDomain_019f3d68-eb5c-7a3d-9486-dc46f91a2e8a" xlink:to="loc_whg_TotalMember_019f3d68-eb5c-72d4-8338-ef28dc707f9c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetRealizedOrUnrealizedGainLossOnTradingSecuritiesAbstract_019f3d68-eb5c-74b1-8879-6c512d251035" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_NetRealizedOrUnrealizedGainLossOnTradingSecuritiesAbstract_019f3d68-eb5c-74b1-8879-6c512d251035" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiGainLossAbstract_019f3d68-eb5c-7737-877f-acd1bc659d12" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquitySecuritiesFvNiGainLossAbstract_019f3d68-eb5c-7737-877f-acd1bc659d12" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_019f3d68-eb5c-77e4-a79a-6878485ad024" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_019f3d68-eb5c-77e4-a79a-6878485ad024" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedloss_019f3d68-eb5c-716a-b86a-f242e4df517c" xlink:href="whg-20260630.xsd#whg_Investmentscarriedatfairvalueunrealizedloss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedloss_019f3d68-eb5c-716a-b86a-f242e4df517c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RealizedInvestmentGainsLosses_019f3d68-eb5c-76c5-b757-164fd54354f8" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_RealizedInvestmentGainsLosses_019f3d68-eb5c-76c5-b757-164fd54354f8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedgain_019f3d68-eb5c-7ac2-a949-6f7229620524" xlink:href="whg-20260630.xsd#whg_Investmentscarriedatfairvalueunrealizedgain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedgain_019f3d68-eb5c-7ac2-a949-6f7229620524" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_019f3d68-eb5c-7983-b184-998b0beaa7f6" xlink:href="whg-20260630.xsd#whg_UnrealizedGainsLossesOnPrivateInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_019f3d68-eb5c-7983-b184-998b0beaa7f6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostMethodInvestments_019f3d68-eb5c-7bdf-a660-632452e2e963" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_CostMethodInvestments_019f3d68-eb5c-7bdf-a660-632452e2e963" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_019f3d68-eb5c-79da-95a9-5bb57cbd0175" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_019f3d68-eb5c-79da-95a9-5bb57cbd0175" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingUnrealizedGain_019f3d68-eb5c-7084-9192-02da7c6508d6" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_DebtSecuritiesTradingUnrealizedGain_019f3d68-eb5c-7084-9192-02da7c6508d6" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingUnrealizedLoss_019f3d68-eb5c-74f8-98e1-42c35731a3d0" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_DebtSecuritiesTradingUnrealizedLoss_019f3d68-eb5c-74f8-98e1-42c35731a3d0" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebt_019f3d68-eb5c-761b-84c3-13758bc57bbb" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_TradingSecuritiesDebt_019f3d68-eb5c-761b-84c3-13758bc57bbb" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiCost_019f3d68-eb5c-7287-861b-4ae18637ea0d" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquitySecuritiesFvNiCost_019f3d68-eb5c-7287-861b-4ae18637ea0d" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGain_019f3d68-eb5c-7f19-a4fd-eb4e920c0ef2" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedGain_019f3d68-eb5c-7f19-a4fd-eb4e920c0ef2" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNiUnrealizedLoss_019f3d68-eb5c-781e-946f-a0dd309bfd3c" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquitySecuritiesFvNiUnrealizedLoss_019f3d68-eb5c-781e-946f-a0dd309bfd3c" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_019f3d68-eb5c-7cac-8ab9-a3fb2b3ece9f" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_019f3d68-eb5c-7cac-8ab9-a3fb2b3ece9f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost_019f3d68-eb5c-7666-b444-e33a2e1a3c64" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_DebtSecuritiesTradingAndEquitySecuritiesFvNiCost_019f3d68-eb5c-7666-b444-e33a2e1a3c64" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain_019f3d68-eb5c-7f0c-bb09-061c3a2b368e" xlink:href="whg-20260630.xsd#whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedGain_019f3d68-eb5c-7f0c-bb09-061c3a2b368e" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss_019f3d68-eb5c-7b00-8b5c-c13a38e8c78d" xlink:href="whg-20260630.xsd#whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_DebtSecuritiesTradingAndEquitySecuritiesUnrealizedLoss_019f3d68-eb5c-7b00-8b5c-c13a38e8c78d" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7744-b913-cc64c001c9c8" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7744-b913-cc64c001c9c8" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_019f3d68-eb5c-71ca-baed-2af94bd0172e" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_LongTermInvestments_019f3d68-eb5c-71ca-baed-2af94bd0172e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019f3d68-eb5c-7a38-a94a-4ecc80634a4f" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019f3d68-eb5c-7a38-a94a-4ecc80634a4f" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongtermInvestmentsCarriedatFairValue_019f3d68-eb5c-7ddb-93a2-fa32d4c5e1e8" xlink:href="whg-20260630.xsd#whg_LongtermInvestmentsCarriedatFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_LongtermInvestmentsCarriedatFairValue_019f3d68-eb5c-7ddb-93a2-fa32d4c5e1e8" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_019f3d68-eb5c-70eb-b891-cd5c16f0f697" xlink:href="whg-20260630.xsd#whg_LongTermInvestmentsCarriedAtFairValueUsingNAV"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_019f3d68-eb5c-70eb-b891-cd5c16f0f697" xlink:type="arc" order="23"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019f3d68-eb5c-7a88-a563-dcbe2ca124aa" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_EquityMethodInvestments_019f3d68-eb5c-7a88-a563-dcbe2ca124aa" xlink:type="arc" order="24"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_019f3d68-eb5c-79c6-945b-4d4d0c2c9a28" 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_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_019f3d68-eb5c-79c6-945b-4d4d0c2c9a28" xlink:type="arc" order="25"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentsUnderFairValueMeasurementAlternative_019f3d68-eb5c-7d23-9bb9-4bc9053b28cb" xlink:href="whg-20260630.xsd#whg_InvestmentsUnderFairValueMeasurementAlternative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_InvestmentsUnderFairValueMeasurementAlternative_019f3d68-eb5c-7d23-9bb9-4bc9053b28cb" xlink:type="arc" order="26"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalInvestments_019f3d68-eb5c-72d3-98aa-b2101d3bd00d" xlink:href="whg-20260630.xsd#whg_TotalInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_TotalInvestments_019f3d68-eb5c-72d3-98aa-b2101d3bd00d" xlink:type="arc" order="27"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestCloudPrivateInvestment_019f3d68-eb5c-71d1-adfb-9890ffc124bd" xlink:href="whg-20260630.xsd#whg_InvestCloudPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_InvestCloudPrivateInvestment_019f3d68-eb5c-71d1-adfb-9890ffc124bd" xlink:type="arc" order="28"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueVista_019f3d68-eb5c-7a9c-abc1-70705154e9be" xlink:href="whg-20260630.xsd#whg_InvestmentCarryingValueVista"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_InvestmentCarryingValueVista_019f3d68-eb5c-7a9c-abc1-70705154e9be" xlink:type="arc" order="29"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WEBsPreferredStock_019f3d68-eb5c-7ec3-8c07-45c798049196" xlink:href="whg-20260630.xsd#whg_WEBsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_WEBsPreferredStock_019f3d68-eb5c-7ec3-8c07-45c798049196" xlink:type="arc" order="30"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WEBsCallOption_019f3d68-eb5c-7ed7-b2dc-eede9e632dc8" xlink:href="whg-20260630.xsd#whg_WEBsCallOption"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_WEBsCallOption_019f3d68-eb5c-7ed7-b2dc-eede9e632dc8" xlink:type="arc" order="31"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TXSEPrivateInvestment_019f3d68-eb5c-7a5c-afa1-2436fe9371a0" xlink:href="whg-20260630.xsd#whg_TXSEPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_TXSEPrivateInvestment_019f3d68-eb5c-7a5c-afa1-2436fe9371a0" xlink:type="arc" order="32"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueRidgeline_019f3d68-eb5c-76b8-9d50-fa4b1571d96d" xlink:href="whg-20260630.xsd#whg_InvestmentCarryingValueRidgeline"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_InvestmentCarryingValueRidgeline_019f3d68-eb5c-76b8-9d50-fa4b1571d96d" xlink:type="arc" order="33"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TotalInvestmentsUnderMeasurementAlternative_019f3d68-eb5c-77c5-b7fd-b818b7cfcaa1" xlink:href="whg-20260630.xsd#whg_TotalInvestmentsUnderMeasurementAlternative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_TotalInvestmentsUnderMeasurementAlternative_019f3d68-eb5c-77c5-b7fd-b818b7cfcaa1" xlink:type="arc" order="34"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RealizedGainOnPrivateInvestment_019f3d68-eb5c-739b-9f51-59cc10e0dbce" xlink:href="whg-20260630.xsd#whg_RealizedGainOnPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_019f3d68-eb5c-7d68-b27c-de5d59ce4830" xlink:to="loc_whg_RealizedGainOnPrivateInvestment_019f3d68-eb5c-739b-9f51-59cc10e0dbce" xlink:type="arc" order="35"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/INVESTMENTSDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5c-7459-b11b-53dc5bc25412" 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_019f3d68-eb5c-7b66-9052-22a97151d79c" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_ScheduleOfInvestmentsTable_019f3d68-eb5c-7b66-9052-22a97151d79c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5c-7cfb-9843-797b345cf92d" 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_019f3d68-eb5c-7b66-9052-22a97151d79c" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5c-7cfb-9843-797b345cf92d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5c-7cfb-9843-797b345cf92d_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_019f3d68-eb5c-7cfb-9843-797b345cf92d" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5c-7cfb-9843-797b345cf92d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5c-74e0-b64c-a4efa29a5e1f" 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_019f3d68-eb5c-7cfb-9843-797b345cf92d" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5c-74e0-b64c-a4efa29a5e1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityMember_019f3d68-eb5c-7e14-81fa-0ade1ff9a20b" xlink:href="whg-20260630.xsd#whg_VariableInterestEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5c-74e0-b64c-a4efa29a5e1f" xlink:to="loc_whg_VariableInterestEntityMember_019f3d68-eb5c-7e14-81fa-0ade1ff9a20b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7b4c-9537-fa16e501ea75" 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_019f3d68-eb5c-7b66-9052-22a97151d79c" xlink:to="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7b4c-9537-fa16e501ea75" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7b4c-9537-fa16e501ea75_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_019f3d68-eb5c-7b4c-9537-fa16e501ea75" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7b4c-9537-fa16e501ea75_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-71e9-a2a1-8ae9f9127abc" 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_019f3d68-eb5c-7b4c-9537-fa16e501ea75" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-71e9-a2a1-8ae9f9127abc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UsGaap_EquitySecuritiesMemberMember_019f3d68-eb5c-7e11-8141-7712b16be43f" xlink:href="whg-20260630.xsd#whg_UsGaap_EquitySecuritiesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-71e9-a2a1-8ae9f9127abc" xlink:to="loc_whg_UsGaap_EquitySecuritiesMemberMember_019f3d68-eb5c-7e11-8141-7712b16be43f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_019f3d68-eb5c-72ee-af12-89f709e16be4" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_LongTermInvestments_019f3d68-eb5c-72ee-af12-89f709e16be4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7b5f-b697-74b70419cab3" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7b5f-b697-74b70419cab3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainOnSecurities_019f3d68-eb5c-7d57-8a9c-be4c80547366" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_UnrealizedGainOnSecurities_019f3d68-eb5c-7d57-8a9c-be4c80547366" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInvestments_019f3d68-eb5c-7106-a7d3-46d83970d6f0" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_GainLossOnInvestments_019f3d68-eb5c-7106-a7d3-46d83970d6f0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Investmentscarriedatfairvalueunrealizedgain_019f3d68-eb5c-7eb5-b489-6450b30156ea" xlink:href="whg-20260630.xsd#whg_Investmentscarriedatfairvalueunrealizedgain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_Investmentscarriedatfairvalueunrealizedgain_019f3d68-eb5c-7eb5-b489-6450b30156ea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_019f3d68-eb5c-7380-ade8-0b604b823715" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_TradingSecuritiesDebtAmortizedCost_019f3d68-eb5c-7380-ade8-0b604b823715" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_019f3d68-eb5c-7761-8fdf-08a5ace8db80" xlink:href="whg-20260630.xsd#whg_UnrealizedGainsLossesOnPrivateInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_UnrealizedGainsLossesOnPrivateInvestments_019f3d68-eb5c-7761-8fdf-08a5ace8db80" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostMethodInvestments_019f3d68-eb5c-7cc8-9e16-0cf098b198b8" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_CostMethodInvestments_019f3d68-eb5c-7cc8-9e16-0cf098b198b8" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_019f3d68-eb5c-753c-ba7f-efbba5edb2f9" xlink:href="whg-20260630.xsd#whg_LongTermInvestmentsCarriedAtFairValueUsingNAV"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_LongTermInvestmentsCarriedAtFairValueUsingNAV_019f3d68-eb5c-753c-ba7f-efbba5edb2f9" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019f3d68-eb5c-7ad2-98cf-c6c61fd9bbfe" 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_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_019f3d68-eb5c-7ad2-98cf-c6c61fd9bbfe" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestment_019f3d68-eb5c-7542-a29f-5f36b2707215" xlink:href="whg-20260630.xsd#whg_CarryingValuePrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_CarryingValuePrivateInvestment_019f3d68-eb5c-7542-a29f-5f36b2707215" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentCarryingValueVista_019f3d68-eb5c-79a2-882c-b654c725863d" xlink:href="whg-20260630.xsd#whg_InvestmentCarryingValueVista"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_InvestmentCarryingValueVista_019f3d68-eb5c-79a2-882c-b654c725863d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestmentTxStockExchange_019f3d68-eb5c-7f49-8971-031b74dfb383" xlink:href="whg-20260630.xsd#whg_CarryingValuePrivateInvestmentTxStockExchange"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_CarryingValuePrivateInvestmentTxStockExchange_019f3d68-eb5c-7f49-8971-031b74dfb383" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CarryingValuePrivateInvestmentFunds_019f3d68-eb5c-7dfe-b5e5-0de2e871f1d1" xlink:href="whg-20260630.xsd#whg_CarryingValuePrivateInvestmentFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_CarryingValuePrivateInvestmentFunds_019f3d68-eb5c-7dfe-b5e5-0de2e871f1d1" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnInvestments_019f3d68-eb5c-7a9f-9040-a8402175d18e" 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_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_us-gaap_UnrealizedGainLossOnInvestments_019f3d68-eb5c-7a9f-9040-a8402175d18e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RealizedGainOnPrivateInvestment_019f3d68-eb5c-70ad-9509-d87eda6a7e3d" xlink:href="whg-20260630.xsd#whg_RealizedGainOnPrivateInvestment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ScheduleOfInvestmentsLineItems_019f3d68-eb5c-7459-b11b-53dc5bc25412" xlink:to="loc_whg_RealizedGainOnPrivateInvestment_019f3d68-eb5c-70ad-9509-d87eda6a7e3d" xlink:type="arc" order="15"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/FAIRVALUEMEASUREMENTSDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" 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_019f3d68-eb5c-7eac-b217-44b20c36b791" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_019f3d68-eb5c-7eac-b217-44b20c36b791" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7091-a54a-4a9bf9863674" 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_019f3d68-eb5c-7eac-b217-44b20c36b791" xlink:to="loc_us-gaap_InvestmentTypeAxis_019f3d68-eb5c-7091-a54a-4a9bf9863674" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7091-a54a-4a9bf9863674_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_019f3d68-eb5c-7091-a54a-4a9bf9863674" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-7091-a54a-4a9bf9863674_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-76b3-b4c2-00731d39eaaf" 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_019f3d68-eb5c-7091-a54a-4a9bf9863674" xlink:to="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-76b3-b4c2-00731d39eaaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PrivateEquityFundsMember_019f3d68-eb5c-72dd-99c2-fb25b70ff2f6" 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_019f3d68-eb5c-76b3-b4c2-00731d39eaaf" xlink:to="loc_us-gaap_PrivateEquityFundsMember_019f3d68-eb5c-72dd-99c2-fb25b70ff2f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5c-7890-8d61-5df878efbb3e" xlink:href="whg-20260630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InvestmentTypeCategorizationMember_019f3d68-eb5c-76b3-b4c2-00731d39eaaf" xlink:to="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5c-7890-8d61-5df878efbb3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2" 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_019f3d68-eb5c-7eac-b217-44b20c36b791" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2_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_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" 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_019f3d68-eb5c-7b99-a3de-55bf3a01f9c2" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019f3d68-eb5c-7333-8161-735bb0be165b" 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_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019f3d68-eb5c-7333-8161-735bb0be165b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019f3d68-eb5c-7feb-a008-27fa09e7a5e1" 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_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019f3d68-eb5c-7feb-a008-27fa09e7a5e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019f3d68-eb5c-75ec-bae3-cd8460226c10" 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_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019f3d68-eb5c-75ec-bae3-cd8460226c10" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019f3d68-eb5c-7a95-ba3b-4d5faaff1fd1" 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_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_019f3d68-eb5c-7a95-ba3b-4d5faaff1fd1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsRecurringMember_019f3d68-eb5c-78d6-9fdf-dd01f31b287a" 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_019f3d68-eb5c-7a4a-864a-f6b55e2b4672" xlink:to="loc_us-gaap_FairValueMeasurementsRecurringMember_019f3d68-eb5c-78d6-9fdf-dd01f31b287a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_019f3d68-eb5c-7a63-b635-5f8b014004ae" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosureAbstract_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecuritiesDebt_019f3d68-eb5c-7d02-9632-4484629cab1c" 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_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:to="loc_us-gaap_TradingSecuritiesDebt_019f3d68-eb5c-7d02-9632-4484629cab1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquitySecuritiesFvNi_019f3d68-eb5c-794e-b5a8-f00ee4e6d2eb" 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_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:to="loc_us-gaap_EquitySecuritiesFvNi_019f3d68-eb5c-794e-b5a8-f00ee4e6d2eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7997-a4d0-96d4642259e4" 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_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5c-7997-a4d0-96d4642259e4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityFairValueByFairValueHierarchyLevelExtensibleList_019f3d68-eb5c-74d2-afe2-9df95f909e9b" 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_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiabilityFairValueByFairValueHierarchyLevelExtensibleList_019f3d68-eb5c-74d2-afe2-9df95f909e9b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_019f3d68-eb5c-7fa0-964b-7884d3556015" 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_019f3d68-eb5c-7a63-b635-5f8b014004ae" xlink:to="loc_us-gaap_OtherLiabilitiesFairValueDisclosure_019f3d68-eb5c-7fa0-964b-7884d3556015" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f3d68-eb5c-796e-b24d-7fd0cda61d23" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationCalculationRollForward_019f3d68-eb5c-796e-b24d-7fd0cda61d23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019f3d68-eb5c-77d5-ad46-207a7df1bd49" 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_019f3d68-eb5c-796e-b24d-7fd0cda61d23" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019f3d68-eb5c-77d5-ad46-207a7df1bd49" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_019f3d68-eb5c-762a-8223-e22c3533c60b" 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_019f3d68-eb5c-796e-b24d-7fd0cda61d23" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInOtherComprehensiveIncomeLoss_019f3d68-eb5c-762a-8223-e22c3533c60b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_019f3d68-eb5c-78db-862f-774367d31412" 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_019f3d68-eb5c-77b2-9db8-6fc8f4facf62" 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_019f3d68-eb5c-796e-b24d-7fd0cda61d23" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPeriodIncreaseDecrease_019f3d68-eb5c-77b2-9db8-6fc8f4facf62" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_019f3d68-eb5c-73f7-9ccc-e6b178d108a9" 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_019f3d68-eb5c-796e-b24d-7fd0cda61d23" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSales_019f3d68-eb5c-73f7-9ccc-e6b178d108a9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_FairValueInputsAbstract_019f3d68-eb5c-7a2f-85f3-e5308ee7b418" xlink:href="whg-20260630.xsd#whg_FairValueInputsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_FairValueInputsAbstract_019f3d68-eb5c-7a2f-85f3-e5308ee7b418" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsSensitivityAnalysisDescription_019f3d68-eb5c-7f67-bc06-fa0f7e26d940" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_FairValueMeasurementsSensitivityAnalysisDescription_019f3d68-eb5c-7f67-bc06-fa0f7e26d940" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleMinimum_019f3d68-eb5c-7f5e-aa27-51277a802e92" xlink:href="whg-20260630.xsd#whg_UnobservableInputBookValueMultipleMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputBookValueMultipleMinimum_019f3d68-eb5c-7f5e-aa27-51277a802e92" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleMaximum_019f3d68-eb5c-727c-b8f3-740e775f6bbd" xlink:href="whg-20260630.xsd#whg_UnobservableInputBookValueMultipleMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputBookValueMultipleMaximum_019f3d68-eb5c-727c-b8f3-740e775f6bbd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputBookValueMultipleWeightedAverage_019f3d68-eb5c-79c2-a84d-8f7a2ce29a72" xlink:href="whg-20260630.xsd#whg_UnobservableInputBookValueMultipleWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputBookValueMultipleWeightedAverage_019f3d68-eb5c-79c2-a84d-8f7a2ce29a72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermInvestments_019f3d68-eb5d-7041-8138-8a0ee3684b74" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_LongTermInvestments_019f3d68-eb5d-7041-8138-8a0ee3684b74" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f3d68-eb5d-712e-8001-f305d02fc4da" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_019f3d68-eb5d-712e-8001-f305d02fc4da" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019f3d68-eb5d-7e3b-8726-9ed4216affff" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019f3d68-eb5d-7e3b-8726-9ed4216affff" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f3d68-eb5d-7b94-bdbb-8dee64401caa" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_019f3d68-eb5d-7b94-bdbb-8dee64401caa" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateMaximum_019f3d68-eb5d-7b31-a41c-9ac342cf6774" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateMaximum_019f3d68-eb5d-7b31-a41c-9ac342cf6774" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage_019f3d68-eb5d-78e3-ac4e-459968bdd0f2" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateWeightedAverage_019f3d68-eb5d-78e3-ac4e-459968bdd0f2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionDiscountRateMinimum_019f3d68-eb5d-7551-a010-7e61ab5ac4e3" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionDiscountRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionDiscountRateMinimum_019f3d68-eb5d-7551-a010-7e61ab5ac4e3" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage_019f3d68-eb5d-7a14-a5e9-5ca59307d048" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityWeightedAverage_019f3d68-eb5d-7a14-a5e9-5ca59307d048" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityMaximum_019f3d68-eb5d-713a-8397-cf4566e310fd" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionVolatilityMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityMaximum_019f3d68-eb5d-713a-8397-cf4566e310fd" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputRevenueRetentionVolatilityMinimum_019f3d68-eb5d-70b4-a651-d88a0971d72d" xlink:href="whg-20260630.xsd#whg_UnobservableInputRevenueRetentionVolatilityMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputRevenueRetentionVolatilityMinimum_019f3d68-eb5d-70b4-a651-d88a0971d72d" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateWeightedAverage_019f3d68-eb5d-7f87-8230-c5c631a5de27" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthDiscountRateWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateWeightedAverage_019f3d68-eb5d-7f87-8230-c5c631a5de27" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateMaximum_019f3d68-eb5d-7edf-bd10-7776a5ab6de4" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthDiscountRateMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateMaximum_019f3d68-eb5d-7edf-bd10-7776a5ab6de4" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthDiscountRateMinimum_019f3d68-eb5d-74f9-99b9-5282bd422489" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthDiscountRateMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthDiscountRateMinimum_019f3d68-eb5d-74f9-99b9-5282bd422489" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityWeightedAverage_019f3d68-eb5d-7d0f-9d4f-0cd12acb2e91" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthVolatilityWeightedAverage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthVolatilityWeightedAverage_019f3d68-eb5d-7d0f-9d4f-0cd12acb2e91" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityMaximum_019f3d68-eb5d-7a40-865b-63f70a08c906" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthVolatilityMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthVolatilityMaximum_019f3d68-eb5d-7a40-865b-63f70a08c906" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UnobservableInputGrowthVolatilityMinimum_019f3d68-eb5d-72eb-b216-0bac77bd1dc1" xlink:href="whg-20260630.xsd#whg_UnobservableInputGrowthVolatilityMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_whg_UnobservableInputGrowthVolatilityMinimum_019f3d68-eb5d-72eb-b216-0bac77bd1dc1" xlink:type="arc" order="22"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetAcquisitionConsiderationTransferredContingentConsideration_019f3d68-eb5d-7626-bcc6-c8c816b87fd1" 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_019f3d68-eb5c-7dd4-b825-5b14c7ad9c6a" xlink:to="loc_us-gaap_AssetAcquisitionConsiderationTransferredContingentConsideration_019f3d68-eb5d-7626-bcc6-c8c816b87fd1" xlink:type="arc" order="23"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/GOODWILLANDOTHERINTANGIBLEASSETSDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-757b-8686-13da4333c6eb" 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_019f3d68-eb5d-7e29-b8ff-39cf858db0eb" 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_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_019f3d68-eb5d-7e29-b8ff-39cf858db0eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019f3d68-eb5d-7168-84ad-72d4913cd356" 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_019f3d68-eb5d-7e29-b8ff-39cf858db0eb" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019f3d68-eb5d-7168-84ad-72d4913cd356" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7168-84ad-72d4913cd356_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_019f3d68-eb5d-7168-84ad-72d4913cd356" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7168-84ad-72d4913cd356_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7300-ac93-a5157765cd84" 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_019f3d68-eb5d-7168-84ad-72d4913cd356" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7300-ac93-a5157765cd84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustSegmentGoodwill_019f3d68-eb5d-702e-b5fd-781ae683bf15" xlink:href="whg-20260630.xsd#whg_TrustSegmentGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_whg_TrustSegmentGoodwill_019f3d68-eb5d-702e-b5fd-781ae683bf15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisorySegmentGoodwill_019f3d68-eb5d-78a0-b9a4-966e40992dce" xlink:href="whg-20260630.xsd#whg_AdvisorySegmentGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_whg_AdvisorySegmentGoodwill_019f3d68-eb5d-78a0-b9a4-966e40992dce" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BalanceAtDecember312021_019f3d68-eb5d-7144-9c53-0e762bdcd1e5" xlink:href="whg-20260630.xsd#whg_BalanceAtDecember312021"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_whg_BalanceAtDecember312021_019f3d68-eb5d-7144-9c53-0e762bdcd1e5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_019f3d68-eb5d-777f-a2bc-218791b5d5b1" 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_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_019f3d68-eb5d-777f-a2bc-218791b5d5b1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AcquiredGoodwillTotal_019f3d68-eb5d-7a6d-bcad-aecf255700f0" xlink:href="whg-20260630.xsd#whg_AcquiredGoodwillTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_whg_AcquiredGoodwillTotal_019f3d68-eb5d-7a6d-bcad-aecf255700f0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019f3d68-eb5d-7298-8861-3d6066bcf806" 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_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_us-gaap_GoodwillPurchaseAccountingAdjustments_019f3d68-eb5d-7298-8861-3d6066bcf806" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_GoodwillAdjustmentsTotal_019f3d68-eb5d-7c43-8359-5abd8cd6d6b4" xlink:href="whg-20260630.xsd#whg_GoodwillAdjustmentsTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_whg_GoodwillAdjustmentsTotal_019f3d68-eb5d-7c43-8359-5abd8cd6d6b4" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_019f3d68-eb5d-7637-a089-aad2185f2813" 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_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_019f3d68-eb5d-7637-a089-aad2185f2813" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentForAmortization_019f3d68-eb5d-7be3-b829-9b23e88f5bd2" 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_019f3d68-eb5d-757b-8686-13da4333c6eb" xlink:to="loc_us-gaap_AdjustmentForAmortization_019f3d68-eb5d-7be3-b829-9b23e88f5bd2" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-768f-91e1-f1f5b490c9e1" 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_019f3d68-eb5d-72b9-bfe4-b313fd9b8599" 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_019f3d68-eb5d-768f-91e1-f1f5b490c9e1" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019f3d68-eb5d-72b9-bfe4-b313fd9b8599" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7ea2-9c15-77a73e882b5d" 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_019f3d68-eb5d-72b9-bfe4-b313fd9b8599" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7ea2-9c15-77a73e882b5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7ea2-9c15-77a73e882b5d_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_019f3d68-eb5d-7ea2-9c15-77a73e882b5d" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7ea2-9c15-77a73e882b5d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7fa4-bcf3-46f17a50f9ac" 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_019f3d68-eb5d-7ea2-9c15-77a73e882b5d" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7fa4-bcf3-46f17a50f9ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityMember_019f3d68-eb5d-7ba3-a4fb-ee2ffb88817f" xlink:href="whg-20260630.xsd#whg_VariableInterestEntityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7fa4-bcf3-46f17a50f9ac" xlink:to="loc_whg_VariableInterestEntityMember_019f3d68-eb5d-7ba3-a4fb-ee2ffb88817f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7bcb-8bd4-a9b497180700" xlink:href="whg-20260630.xsd#whg_CommonTrustFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7fa4-bcf3-46f17a50f9ac" xlink:to="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7bcb-8bd4-a9b497180700" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7218-9a43-0a1568402b37" xlink:href="whg-20260630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7fa4-bcf3-46f17a50f9ac" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7218-9a43-0a1568402b37" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5d-768e-a37b-5eb4b5df1b15" 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_019f3d68-eb5d-768f-91e1-f1f5b490c9e1" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5d-768e-a37b-5eb4b5df1b15" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityRevenues_019f3d68-eb5d-7a2a-8336-4ef7965aea0b" 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_019f3d68-eb5d-768f-91e1-f1f5b490c9e1" xlink:to="loc_us-gaap_VariableInterestEntityActivityBetweenVIEAndEntityRevenues_019f3d68-eb5d-7a2a-8336-4ef7965aea0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentOwnedAtFairValue_019f3d68-eb5d-7745-9db1-6b1eba54230c" 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_019f3d68-eb5d-768f-91e1-f1f5b490c9e1" xlink:to="loc_us-gaap_InvestmentOwnedAtFairValue_019f3d68-eb5d-7745-9db1-6b1eba54230c" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/VARIABLEINTERESTENTITIESDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7c3b-a3d3-aa42d90cdbc5" 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_019f3d68-eb5d-789e-9d2d-cb69e8573129" 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_019f3d68-eb5d-7c3b-a3d3-aa42d90cdbc5" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019f3d68-eb5d-789e-9d2d-cb69e8573129" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7d35-88a7-2af56cfe9176" 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_019f3d68-eb5d-789e-9d2d-cb69e8573129" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7d35-88a7-2af56cfe9176" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7d35-88a7-2af56cfe9176_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_019f3d68-eb5d-7d35-88a7-2af56cfe9176" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7d35-88a7-2af56cfe9176_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" 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_019f3d68-eb5d-7d35-88a7-2af56cfe9176" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodFundsMember_019f3d68-eb5d-724a-995d-c0e67e1bc0e2" xlink:href="whg-20260630.xsd#whg_WestwoodFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_WestwoodFundsMember_019f3d68-eb5d-724a-995d-c0e67e1bc0e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7483-a3b9-a255530e00cf" xlink:href="whg-20260630.xsd#whg_CommonTrustFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7483-a3b9-a255530e00cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7e2d-b490-2ea0a3647639" xlink:href="whg-20260630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7e2d-b490-2ea0a3647639" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodHospitalityFundILLCMember_019f3d68-eb5d-7d61-9041-820442a3134d" xlink:href="whg-20260630.xsd#whg_WestwoodHospitalityFundILLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_WestwoodHospitalityFundILLCMember_019f3d68-eb5d-7d61-9041-820442a3134d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-76bf-9d1c-a03e65a1eb5e" xlink:href="whg-20260630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-76bf-9d1c-a03e65a1eb5e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateWealthMember_019f3d68-eb5d-7939-91dd-2e415a069464" xlink:href="whg-20260630.xsd#whg_PrivateWealthMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_PrivateWealthMember_019f3d68-eb5d-7939-91dd-2e415a069464" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InstitutionalMember_019f3d68-eb5d-75c7-b8fe-55bb6aafd3ae" xlink:href="whg-20260630.xsd#whg_InstitutionalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7e4c-81d0-efc2090b8c13" xlink:to="loc_whg_InstitutionalMember_019f3d68-eb5d-75c7-b8fe-55bb6aafd3ae" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_019f3d68-eb5d-76a0-a114-ee3f2c46bc4e" xlink:href="whg-20260630.xsd#whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019f3d68-eb5d-7c3b-a3d3-aa42d90cdbc5" xlink:to="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_019f3d68-eb5d-76a0-a114-ee3f2c46bc4e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsUnderManagementCarryingAmount_019f3d68-eb5d-7af0-a964-7325e5a9f0f3" 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_019f3d68-eb5d-76a0-a114-ee3f2c46bc4e" xlink:to="loc_us-gaap_AssetsUnderManagementCarryingAmount_019f3d68-eb5d-7af0-a964-7325e5a9f0f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5d-7c2f-ad46-eff0203fe774" 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_019f3d68-eb5d-76a0-a114-ee3f2c46bc4e" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5d-7c2f-ad46-eff0203fe774" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RiskOfLoss_019f3d68-eb5d-7dd0-9e49-fe1bb9db3bc5" xlink:href="whg-20260630.xsd#whg_RiskOfLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_whg_VariableInterestEntityConsolidatedCarryingAmountAssetsAndLiabilitiesAbstract_019f3d68-eb5d-76a0-a114-ee3f2c46bc4e" xlink:to="loc_whg_RiskOfLoss_019f3d68-eb5d-7dd0-9e49-fe1bb9db3bc5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_VariableInterestEntityConsolidatedAssetsNoncurrent_019f3d68-eb5d-70ba-9d23-eef46f4f46b3" xlink:href="whg-20260630.xsd#whg_VariableInterestEntityConsolidatedAssetsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019f3d68-eb5d-7c3b-a3d3-aa42d90cdbc5" xlink:to="loc_whg_VariableInterestEntityConsolidatedAssetsNoncurrent_019f3d68-eb5d-70ba-9d23-eef46f4f46b3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/REVENUEDisaggregationofRevenueDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7003-9565-4ff443951a75" 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_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" 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_019f3d68-eb5d-7003-9565-4ff443951a75" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f3d68-eb5d-7b15-90ed-6c289a4eda43" 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_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" xlink:to="loc_srt_ProductOrServiceAxis_019f3d68-eb5d-7b15-90ed-6c289a4eda43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7b15-90ed-6c289a4eda43_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_019f3d68-eb5d-7b15-90ed-6c289a4eda43" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7b15-90ed-6c289a4eda43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" 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_019f3d68-eb5d-7b15-90ed-6c289a4eda43" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InvestmentAdvisoryServicesMember_019f3d68-eb5d-722b-8398-610cca6a4560" xlink:href="whg-20260630.xsd#whg_InvestmentAdvisoryServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_InvestmentAdvisoryServicesMember_019f3d68-eb5d-722b-8398-610cca6a4560" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundAdvisoryMemberMember_019f3d68-eb5d-7ede-97c3-447aa377bfe8" xlink:href="whg-20260630.xsd#whg_MutualFundAdvisoryMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_MutualFundAdvisoryMemberMember_019f3d68-eb5d-7ede-97c3-447aa377bfe8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateWealthAdvisoryMember_019f3d68-eb5d-7c13-bdf2-d13c47f8879b" xlink:href="whg-20260630.xsd#whg_PrivateWealthAdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_PrivateWealthAdvisoryMember_019f3d68-eb5d-7c13-bdf2-d13c47f8879b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PerformancefeeMember_019f3d68-eb5d-7d06-b2e1-1b2dd8e33e89" xlink:href="whg-20260630.xsd#whg_PerformancefeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_PerformancefeeMember_019f3d68-eb5d-7d06-b2e1-1b2dd8e33e89" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustFeeMember_019f3d68-eb5d-7736-ba68-946a230f16b9" xlink:href="whg-20260630.xsd#whg_TrustFeeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_TrustFeeMember_019f3d68-eb5d-7736-ba68-946a230f16b9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_OtherRevenueMiscServicesMember_019f3d68-eb5d-7c13-8ba2-5e4f915eb04e" xlink:href="whg-20260630.xsd#whg_OtherRevenueMiscServicesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_OtherRevenueMiscServicesMember_019f3d68-eb5d-7c13-8ba2-5e4f915eb04e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedMember_019f3d68-eb5d-787b-b231-755223b29b98" xlink:href="whg-20260630.xsd#whg_TrustPerformanceBasedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7930-bfe6-98e8f586ce93" xlink:to="loc_whg_TrustPerformanceBasedMember_019f3d68-eb5d-787b-b231-755223b29b98" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-7bc6-ae99-7b7653013c15" 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_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-7bc6-ae99-7b7653013c15" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7bc6-ae99-7b7653013c15_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_019f3d68-eb5d-7bc6-ae99-7b7653013c15" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7bc6-ae99-7b7653013c15_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-767b-b836-f0634fca0602" 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_019f3d68-eb5d-7bc6-ae99-7b7653013c15" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-767b-b836-f0634fca0602" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustMember_019f3d68-eb5d-71c6-89c0-dd97ee650e01" xlink:href="whg-20260630.xsd#whg_TrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f3d68-eb5d-767b-b836-f0634fca0602" xlink:to="loc_whg_TrustMember_019f3d68-eb5d-71c6-89c0-dd97ee650e01" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisoryMember_019f3d68-eb5d-7a2c-8e5c-c2f5fa884927" xlink:href="whg-20260630.xsd#whg_AdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f3d68-eb5d-767b-b836-f0634fca0602" xlink:to="loc_whg_AdvisoryMember_019f3d68-eb5d-7a2c-8e5c-c2f5fa884927" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelAxis_019f3d68-eb5d-762b-a0b1-dd55903ea354" 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_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelAxis_019f3d68-eb5d-762b-a0b1-dd55903ea354" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelDomain_019f3d68-eb5d-762b-a0b1-dd55903ea354_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_019f3d68-eb5d-762b-a0b1-dd55903ea354" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelDomain_019f3d68-eb5d-762b-a0b1-dd55903ea354_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContractWithCustomerSalesChannelDomain_019f3d68-eb5d-703a-909e-8b24c3ecbede" 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_019f3d68-eb5d-762b-a0b1-dd55903ea354" xlink:to="loc_us-gaap_ContractWithCustomerSalesChannelDomain_019f3d68-eb5d-703a-909e-8b24c3ecbede" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_019f3d68-eb5d-71f5-b542-390c52342dbf" 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_019f3d68-eb5d-7d63-98cd-fe2ad336cc5e" xlink:to="loc_srt_StatementGeographicalAxis_019f3d68-eb5d-71f5-b542-390c52342dbf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f3d68-eb5d-71f5-b542-390c52342dbf_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_019f3d68-eb5d-71f5-b542-390c52342dbf" xlink:to="loc_srt_SegmentGeographicalDomain_019f3d68-eb5d-71f5-b542-390c52342dbf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_019f3d68-eb5d-72be-b68f-12a9ec1b88c5" 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_019f3d68-eb5d-71f5-b542-390c52342dbf" xlink:to="loc_srt_SegmentGeographicalDomain_019f3d68-eb5d-72be-b68f-12a9ec1b88c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_019f3d68-eb5d-7b2a-8337-2ea0ef35ae13" 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_019f3d68-eb5d-72be-b68f-12a9ec1b88c5" xlink:to="loc_srt_EuropeMember_019f3d68-eb5d-7b2a-8337-2ea0ef35ae13" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_019f3d68-eb5d-7c44-851a-b43d4cd0e412" 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_019f3d68-eb5d-72be-b68f-12a9ec1b88c5" xlink:to="loc_country_CA_019f3d68-eb5d-7c44-851a-b43d4cd0e412" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_019f3d68-eb5d-7a47-bcab-cd2eb7ec83f3" 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_019f3d68-eb5d-72be-b68f-12a9ec1b88c5" xlink:to="loc_country_US_019f3d68-eb5d-7a47-bcab-cd2eb7ec83f3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f3d68-eb5d-7d66-b4ac-09b19d238745" 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_019f3d68-eb5d-7003-9565-4ff443951a75" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_019f3d68-eb5d-7d66-b4ac-09b19d238745" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7898-8c51-a55923368a25" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_019f3d68-eb5d-7676-bbfe-6007d663241a" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_us-gaap_VestingAxis_019f3d68-eb5d-7676-bbfe-6007d663241a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019f3d68-eb5d-7676-bbfe-6007d663241a_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_019f3d68-eb5d-7676-bbfe-6007d663241a" xlink:to="loc_us-gaap_VestingDomain_019f3d68-eb5d-7676-bbfe-6007d663241a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_019f3d68-eb5d-7e46-a92c-b3d5fc165e50" 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_019f3d68-eb5d-7676-bbfe-6007d663241a" xlink:to="loc_us-gaap_VestingDomain_019f3d68-eb5d-7e46-a92c-b3d5fc165e50" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetAxis_019f3d68-eb5d-7049-8085-597528e18969" xlink:href="whg-20260630.xsd#whg_TargetAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_whg_TargetAxis_019f3d68-eb5d-7049-8085-597528e18969" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetDomain_019f3d68-eb5d-7049-8085-597528e18969_default" xlink:href="whg-20260630.xsd#whg_TargetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_whg_TargetAxis_019f3d68-eb5d-7049-8085-597528e18969" xlink:to="loc_whg_TargetDomain_019f3d68-eb5d-7049-8085-597528e18969_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TargetDomain_019f3d68-eb5d-7bc1-85b2-29ef7f3535e6" xlink:href="whg-20260630.xsd#whg_TargetDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_whg_TargetAxis_019f3d68-eb5d-7049-8085-597528e18969" xlink:to="loc_whg_TargetDomain_019f3d68-eb5d-7bc1-85b2-29ef7f3535e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_019f3d68-eb5d-7db9-b569-0dd2dfbd4306" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_srt_RangeAxis_019f3d68-eb5d-7db9-b569-0dd2dfbd4306" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f3d68-eb5d-7db9-b569-0dd2dfbd4306_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_019f3d68-eb5d-7db9-b569-0dd2dfbd4306" xlink:to="loc_srt_RangeMember_019f3d68-eb5d-7db9-b569-0dd2dfbd4306_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_019f3d68-eb5d-726c-b7ba-e3a95fc984e9" 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_019f3d68-eb5d-7db9-b569-0dd2dfbd4306" xlink:to="loc_srt_RangeMember_019f3d68-eb5d-726c-b7ba-e3a95fc984e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-79ef-995c-b83aeadd4758" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-79ef-995c-b83aeadd4758" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-79ef-995c-b83aeadd4758_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_019f3d68-eb5d-79ef-995c-b83aeadd4758" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-79ef-995c-b83aeadd4758_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7986-8fcc-0d323848ac89" 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_019f3d68-eb5d-79ef-995c-b83aeadd4758" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7986-8fcc-0d323848ac89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7700-9051-bca313c42a68" 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_019f3d68-eb5d-7986-8fcc-0d323848ac89" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7700-9051-bca313c42a68" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CanadianPlanMember_019f3d68-eb5d-759b-bdd4-78ce68e1d898" xlink:href="whg-20260630.xsd#whg_CanadianPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7986-8fcc-0d323848ac89" xlink:to="loc_whg_CanadianPlanMember_019f3d68-eb5d-759b-bdd4-78ce68e1d898" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundShareIncentiveAwardsMember_019f3d68-eb5d-740b-84de-4f621d7397f1" xlink:href="whg-20260630.xsd#whg_MutualFundShareIncentiveAwardsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7986-8fcc-0d323848ac89" xlink:to="loc_whg_MutualFundShareIncentiveAwardsMember_019f3d68-eb5d-740b-84de-4f621d7397f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019f3d68-eb5d-7269-8a16-a178953e8db0" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_dei_LegalEntityAxis_019f3d68-eb5d-7269-8a16-a178953e8db0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019f3d68-eb5d-7269-8a16-a178953e8db0_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_019f3d68-eb5d-7269-8a16-a178953e8db0" xlink:to="loc_dei_EntityDomain_019f3d68-eb5d-7269-8a16-a178953e8db0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019f3d68-eb5d-7ef0-8cb7-7b42bf8b468a" 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_019f3d68-eb5d-7269-8a16-a178953e8db0" xlink:to="loc_dei_EntityDomain_019f3d68-eb5d-7ef0-8cb7-7b42bf8b468a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodInternationalAdvisorsIncMember_019f3d68-eb5d-74a5-8c20-74fd6fd38f37" xlink:href="whg-20260630.xsd#whg_WestwoodInternationalAdvisorsIncMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019f3d68-eb5d-7ef0-8cb7-7b42bf8b468a" xlink:to="loc_whg_WestwoodInternationalAdvisorsIncMember_019f3d68-eb5d-74a5-8c20-74fd6fd38f37" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77_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_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_019f3d68-eb5d-768b-81f1-520a42f5b3d0" 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_019f3d68-eb5d-7fcd-a4e4-8a791e89bd77" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_019f3d68-eb5d-768b-81f1-520a42f5b3d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MutualFundMember_019f3d68-eb5d-7377-a247-81e68898e6d7" 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_019f3d68-eb5d-768b-81f1-520a42f5b3d0" xlink:to="loc_us-gaap_MutualFundMember_019f3d68-eb5d-7377-a247-81e68898e6d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f3d68-eb5d-755a-b2e3-669e271165b3" 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_019f3d68-eb5d-7dda-829d-1291aeea8f70" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_019f3d68-eb5d-755a-b2e3-669e271165b3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5d-755a-b2e3-669e271165b3_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_019f3d68-eb5d-755a-b2e3-669e271165b3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5d-755a-b2e3-669e271165b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5d-7e3a-bd2f-bae7d9250389" 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_019f3d68-eb5d-755a-b2e3-669e271165b3" xlink:to="loc_us-gaap_AntidilutiveSecuritiesNameDomain_019f3d68-eb5d-7e3a-bd2f-bae7d9250389" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7018-a464-93ff107b4aca" 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_019f3d68-eb5d-7e3a-bd2f-bae7d9250389" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7018-a464-93ff107b4aca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019f3d68-eb5d-72e5-ad41-c889bec26a63" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_019f3d68-eb5d-72e5-ad41-c889bec26a63" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019f3d68-eb5d-7f2a-afa1-36e5da5e1d10" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_019f3d68-eb5d-7f2a-afa1-36e5da5e1d10" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal_019f3d68-eb5d-730e-9474-f81801a7f31e" xlink:href="whg-20260630.xsd#whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrantOriginal_019f3d68-eb5d-730e-9474-f81801a7f31e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_FundPurchasesOfCommonStock_019f3d68-eb5d-743e-a1dc-f91224eebb73" xlink:href="whg-20260630.xsd#whg_FundPurchasesOfCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_whg_FundPurchasesOfCommonStock_019f3d68-eb5d-743e-a1dc-f91224eebb73" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant_019f3d68-eb5d-7280-b5fd-f8cbee018e75" xlink:href="whg-20260630.xsd#whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_whg_ShareBasedCompensationArrangementByShareBasedPaymentAwardAvailableForGrant_019f3d68-eb5d-7280-b5fd-f8cbee018e75" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharePrice_019f3d68-eb5d-703d-afa0-105fdaba9be1" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_SharePrice_019f3d68-eb5d-703d-afa0-105fdaba9be1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019f3d68-eb5d-7285-b1d2-1fe6b2f499b9" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_PaymentsForRepurchaseOfCommonStock_019f3d68-eb5d-7285-b1d2-1fe6b2f499b9" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_019f3d68-eb5d-72bf-bf01-42b02f36d47d" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_019f3d68-eb5d-72bf-bf01-42b02f36d47d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019f3d68-eb5d-7bab-921a-1a7259c010c1" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedShareBasedAwardsOtherThanOptions_019f3d68-eb5d-7bab-921a-1a7259c010c1" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019f3d68-eb5d-779f-a5d0-99c263c2014f" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_019f3d68-eb5d-779f-a5d0-99c263c2014f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7643-91a9-11ddb0d38fb5" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7643-91a9-11ddb0d38fb5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_019f3d68-eb5d-7d7f-af36-970fc1b6d6de" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardRequisiteServicePeriod1_019f3d68-eb5d-7d7f-af36-970fc1b6d6de" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f3d68-eb5d-7ea0-a237-f9e2a626ef87" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f3d68-eb5d-7ea0-a237-f9e2a626ef87" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_MutualFundIncentiveAwardLiability_019f3d68-eb5d-7764-a202-f79c5f334ded" xlink:href="whg-20260630.xsd#whg_MutualFundIncentiveAwardLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_whg_MutualFundIncentiveAwardLiability_019f3d68-eb5d-7764-a202-f79c5f334ded" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019f3d68-eb5d-7dca-a938-15a3045d8f8f" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_019f3d68-eb5d-7dca-a938-15a3045d8f8f" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockAwardForfeitures_019f3d68-eb5d-7b87-af2e-9893aae5dccc" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_RestrictedStockAwardForfeitures_019f3d68-eb5d-7b87-af2e-9893aae5dccc" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_019f3d68-eb5d-73b9-b074-6cc713ce81e9" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited_019f3d68-eb5d-73b9-b074-6cc713ce81e9" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f3d68-eb5d-7777-b1aa-d6d902771c64" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_019f3d68-eb5d-7777-b1aa-d6d902771c64" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_019f3d68-eb5d-7042-aa5c-856d10b02e4b" 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_019f3d68-eb5d-7898-8c51-a55923368a25" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_019f3d68-eb5d-7042-aa5c-856d10b02e4b" xlink:type="arc" order="18"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7502-8528-1d7c97d6f879" 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_019f3d68-eb5d-7071-bc7b-ff43ef8d3777" 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_019f3d68-eb5d-7502-8528-1d7c97d6f879" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7071-bc7b-ff43ef8d3777" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-72b5-b07c-f160b684eb24" 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_019f3d68-eb5d-7071-bc7b-ff43ef8d3777" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-72b5-b07c-f160b684eb24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-72b5-b07c-f160b684eb24_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_019f3d68-eb5d-72b5-b07c-f160b684eb24" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-72b5-b07c-f160b684eb24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" 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_019f3d68-eb5d-72b5-b07c-f160b684eb24" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DomesticEmployeeServiceAwardMember_019f3d68-eb5d-7f84-aa47-80ec5ac4027d" xlink:href="whg-20260630.xsd#whg_DomesticEmployeeServiceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:to="loc_whg_DomesticEmployeeServiceAwardMember_019f3d68-eb5d-7f84-aa47-80ec5ac4027d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_019f3d68-eb5d-7be8-a5af-3f9da3e591f1" 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_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:to="loc_us-gaap_PerformanceSharesMember_019f3d68-eb5d-7be8-a5af-3f9da3e591f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_DomesticServiceAndPerformanceAwardMember_019f3d68-eb5d-773f-a516-22894598db34" xlink:href="whg-20260630.xsd#whg_DomesticServiceAndPerformanceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:to="loc_whg_DomesticServiceAndPerformanceAwardMember_019f3d68-eb5d-773f-a516-22894598db34" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CanadianEmployeeServiceAwardMember_019f3d68-eb5d-7c76-a3af-1a77790012cc" xlink:href="whg-20260630.xsd#whg_CanadianEmployeeServiceAwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:to="loc_whg_CanadianEmployeeServiceAwardMember_019f3d68-eb5d-7c76-a3af-1a77790012cc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-70aa-8a0d-43ee8f948a5e" 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_019f3d68-eb5d-7bd8-a26d-84ab2ab49eb9" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-70aa-8a0d-43ee8f948a5e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_019f3d68-eb5d-7585-a5cb-e1c61412f1cb" 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_019f3d68-eb5d-7071-bc7b-ff43ef8d3777" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_019f3d68-eb5d-7585-a5cb-e1c61412f1cb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7585-a5cb-e1c61412f1cb_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_019f3d68-eb5d-7585-a5cb-e1c61412f1cb" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7585-a5cb-e1c61412f1cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7e1f-8e49-30f4622c04f8" 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_019f3d68-eb5d-7585-a5cb-e1c61412f1cb" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_019f3d68-eb5d-7e1f-8e49-30f4622c04f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_019f3d68-eb5d-7a3c-9987-fc559df1be34" 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_019f3d68-eb5d-7071-bc7b-ff43ef8d3777" xlink:to="loc_us-gaap_PlanNameAxis_019f3d68-eb5d-7a3c-9987-fc559df1be34" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f3d68-eb5d-7a3c-9987-fc559df1be34_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_019f3d68-eb5d-7a3c-9987-fc559df1be34" xlink:to="loc_us-gaap_PlanNameDomain_019f3d68-eb5d-7a3c-9987-fc559df1be34_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_019f3d68-eb5d-7618-ac47-59fa26393460" 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_019f3d68-eb5d-7a3c-9987-fc559df1be34" xlink:to="loc_us-gaap_PlanNameDomain_019f3d68-eb5d-7618-ac47-59fa26393460" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f3d68-eb5d-7f83-9e93-36f98e455c85" 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_019f3d68-eb5d-7502-8528-1d7c97d6f879" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_019f3d68-eb5d-7f83-9e93-36f98e455c85" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LONGTERMINCENTIVECOMPENSATIONDetails1" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7d98-ba0e-e86f6428ca62" 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_019f3d68-eb5d-7390-b335-3cfaa38221e3" 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_019f3d68-eb5d-7d98-ba0e-e86f6428ca62" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7390-b335-3cfaa38221e3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7ce5-bd58-2be766801130" 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_019f3d68-eb5d-7390-b335-3cfaa38221e3" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7ce5-bd58-2be766801130" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7ce5-bd58-2be766801130_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_019f3d68-eb5d-7ce5-bd58-2be766801130" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7ce5-bd58-2be766801130_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7c70-9a9b-22371453144c" 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_019f3d68-eb5d-7ce5-bd58-2be766801130" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7c70-9a9b-22371453144c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-793f-b454-6c3814abaafb" 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_019f3d68-eb5d-7c70-9a9b-22371453144c" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-793f-b454-6c3814abaafb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f3d68-eb5d-7a3e-b588-0a5131073dad" 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_019f3d68-eb5d-7d98-ba0e-e86f6428ca62" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7d7b-8777-09e1a4d6398d" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7d7b-8777-09e1a4d6398d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f3d68-eb5d-75ac-955d-21985044f6c8" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f3d68-eb5d-75ac-955d-21985044f6c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f3d68-eb5d-702b-9ca0-848a601a68ec" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f3d68-eb5d-702b-9ca0-848a601a68ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f3d68-eb5d-7da9-84a5-993439344be6" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f3d68-eb5d-7da9-84a5-993439344be6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7a7a-81a3-17deca60ea77" 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_019f3d68-eb5d-7436-ac5f-a9a5207bd438" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f3d68-eb5d-7436-ac5f-a9a5207bd438" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-782d-bb45-b1ce77a7c08d" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-782d-bb45-b1ce77a7c08d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-7ebf-aa3c-08ae362efe86" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-7ebf-aa3c-08ae362efe86" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f3d68-eb5d-770d-bcb7-46c572dd6b6f" 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_019f3d68-eb5d-7a3e-b588-0a5131073dad" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f3d68-eb5d-770d-bcb7-46c572dd6b6f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f3d68-eb5d-7311-8c8a-2e13acff0591" 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-20260630.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_019f3d68-eb5d-7389-a11d-5036a4eef46e" 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_019f3d68-eb5d-7ba6-8497-d8fe52f2bc48" 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_019f3d68-eb5d-7389-a11d-5036a4eef46e" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_019f3d68-eb5d-7ba6-8497-d8fe52f2bc48" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-758e-914b-0271d676ce56" 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_019f3d68-eb5d-7ba6-8497-d8fe52f2bc48" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-758e-914b-0271d676ce56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-758e-914b-0271d676ce56_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_019f3d68-eb5d-758e-914b-0271d676ce56" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-758e-914b-0271d676ce56_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7020-b14c-2a43a1b5e4ec" 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_019f3d68-eb5d-758e-914b-0271d676ce56" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7020-b14c-2a43a1b5e4ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_019f3d68-eb5d-74b8-9529-0da83d876a7d" xlink:href="whg-20260630.xsd#whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7020-b14c-2a43a1b5e4ec" xlink:to="loc_whg_RestrictedSharesSubjectToServiceAndPerformanceConditionsMember_019f3d68-eb5d-74b8-9529-0da83d876a7d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f3d68-eb5d-737a-a502-3e744fbeac1a" 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_019f3d68-eb5d-7389-a11d-5036a4eef46e" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7b1c-b49e-5b495a6f9f4a" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7b1c-b49e-5b495a6f9f4a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f3d68-eb5d-7c2c-9626-8850052bc143" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_019f3d68-eb5d-7c2c-9626-8850052bc143" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f3d68-eb5d-7660-b875-53cc3e9ca442" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_019f3d68-eb5d-7660-b875-53cc3e9ca442" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f3d68-eb5d-7b0d-960a-e7790b78fecf" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_019f3d68-eb5d-7b0d-960a-e7790b78fecf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_019f3d68-eb5d-7b55-bd6b-ff0ffa81bd64" 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_019f3d68-eb5d-7ef1-b0a9-2d3dbfc31a69" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f3d68-eb5d-7ef1-b0a9-2d3dbfc31a69" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-746d-9b7c-ab83bd4e6195" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-746d-9b7c-ab83bd4e6195" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-7832-9e46-bf483895fbea" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_019f3d68-eb5d-7832-9e46-bf483895fbea" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f3d68-eb5d-7755-9259-631151c4ccc4" 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_019f3d68-eb5d-737a-a502-3e744fbeac1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_019f3d68-eb5d-7755-9259-631151c4ccc4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_019f3d68-eb5d-703a-a21a-822779c2cbc2" 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-20260630.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_019f3d68-eb5d-7c75-9529-7ee2180af962" 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_019f3d68-eb5d-7536-a8c3-b1e97f7aae4e" 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_019f3d68-eb5d-7c75-9529-7ee2180af962" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019f3d68-eb5d-7536-a8c3-b1e97f7aae4e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019f3d68-eb5d-7582-b2ce-1f8e893f4007" 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_019f3d68-eb5d-7536-a8c3-b1e97f7aae4e" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019f3d68-eb5d-7582-b2ce-1f8e893f4007" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019f3d68-eb5d-7582-b2ce-1f8e893f4007_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_019f3d68-eb5d-7582-b2ce-1f8e893f4007" xlink:to="loc_us-gaap_RelatedPartyDomain_019f3d68-eb5d-7582-b2ce-1f8e893f4007_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019f3d68-eb5d-7c42-8400-37c622cfb047" 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_019f3d68-eb5d-7582-b2ce-1f8e893f4007" xlink:to="loc_us-gaap_RelatedPartyDomain_019f3d68-eb5d-7c42-8400-37c622cfb047" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrustForBenefitOfEmployeesMember_019f3d68-eb5d-7b9e-acc0-e59e1bbf27be" 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_019f3d68-eb5d-7c42-8400-37c622cfb047" xlink:to="loc_us-gaap_TrustForBenefitOfEmployeesMember_019f3d68-eb5d-7b9e-acc0-e59e1bbf27be" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7a97-bd81-8615e7f154ff" 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_019f3d68-eb5d-7536-a8c3-b1e97f7aae4e" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7a97-bd81-8615e7f154ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7a97-bd81-8615e7f154ff_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_019f3d68-eb5d-7a97-bd81-8615e7f154ff" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7a97-bd81-8615e7f154ff_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-72e8-a862-a9436540fc1b" 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_019f3d68-eb5d-7a97-bd81-8615e7f154ff" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-72e8-a862-a9436540fc1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7485-bb2e-b372c266be78" xlink:href="whg-20260630.xsd#whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-72e8-a862-a9436540fc1b" xlink:to="loc_whg_UndertakingForCollectiveInvestmentInTransferableSecuritiesMember_019f3d68-eb5d-7485-bb2e-b372c266be78" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-7a03-9e66-20a674e46281" xlink:href="whg-20260630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-72e8-a862-a9436540fc1b" xlink:to="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-7a03-9e66-20a674e46281" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DueFromRelatedParties_019f3d68-eb5d-7a92-9674-f553a18d151c" 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_019f3d68-eb5d-7c75-9529-7ee2180af962" xlink:to="loc_us-gaap_DueFromRelatedParties_019f3d68-eb5d-7a92-9674-f553a18d151c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromRelatedParties_019f3d68-eb5d-780a-ad73-287642c7bc9a" 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_019f3d68-eb5d-7c75-9529-7ee2180af962" xlink:to="loc_us-gaap_RevenueFromRelatedParties_019f3d68-eb5d-780a-ad73-287642c7bc9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableRelatedPartiesCurrent_019f3d68-eb5d-7d04-89f8-6e420ce45211" 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_019f3d68-eb5d-7c75-9529-7ee2180af962" xlink:to="loc_us-gaap_AccountsReceivableRelatedPartiesCurrent_019f3d68-eb5d-7d04-89f8-6e420ce45211" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_019f3d68-eb5d-70fe-9f83-d1b8ca0d4600" 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_019f3d68-eb5d-7c75-9529-7ee2180af962" xlink:to="loc_us-gaap_RelatedPartyTransactionExpensesFromTransactionsWithRelatedParty_019f3d68-eb5d-70fe-9f83-d1b8ca0d4600" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/LEASESTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" 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_019f3d68-eb5d-7872-8d62-9214bd892428" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_LesseeLeaseDescriptionTable_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_CounterpartyNameAxis_019f3d68-eb5d-7f58-84f8-d4d8d83ed846" 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_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:to="loc_srt_CounterpartyNameAxis_019f3d68-eb5d-7f58-84f8-d4d8d83ed846" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f3d68-eb5d-7f58-84f8-d4d8d83ed846_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_019f3d68-eb5d-7f58-84f8-d4d8d83ed846" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f3d68-eb5d-7f58-84f8-d4d8d83ed846_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f3d68-eb5d-7059-90b3-c9e149d7e37d" 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_019f3d68-eb5d-7f58-84f8-d4d8d83ed846" xlink:to="loc_srt_RepurchaseAgreementCounterpartyNameDomain_019f3d68-eb5d-7059-90b3-c9e149d7e37d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-774a-87db-b65e40c65124" 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_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-774a-87db-b65e40c65124" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-774a-87db-b65e40c65124_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_019f3d68-eb5d-774a-87db-b65e40c65124" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-774a-87db-b65e40c65124_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-713a-8e8e-6f52894be303" 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_019f3d68-eb5d-774a-87db-b65e40c65124" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-713a-8e8e-6f52894be303" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionAxis_019f3d68-eb5d-7b60-b53c-dce889829e61" 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_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:to="loc_us-gaap_GeographicDistributionAxis_019f3d68-eb5d-7b60-b53c-dce889829e61" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_019f3d68-eb5d-7b60-b53c-dce889829e61_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_019f3d68-eb5d-7b60-b53c-dce889829e61" xlink:to="loc_us-gaap_GeographicDistributionDomain_019f3d68-eb5d-7b60-b53c-dce889829e61_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicDistributionDomain_019f3d68-eb5d-71b9-bd52-85d3ec51c1d7" 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_019f3d68-eb5d-7b60-b53c-dce889829e61" xlink:to="loc_us-gaap_GeographicDistributionDomain_019f3d68-eb5d-71b9-bd52-85d3ec51c1d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f3d68-eb5d-7241-a434-e3ec0d459e0d" 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_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_019f3d68-eb5d-7241-a434-e3ec0d459e0d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f3d68-eb5d-7241-a434-e3ec0d459e0d_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_019f3d68-eb5d-7241-a434-e3ec0d459e0d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f3d68-eb5d-7241-a434-e3ec0d459e0d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f3d68-eb5d-74ea-b1d7-6e01292896cb" 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_019f3d68-eb5d-7241-a434-e3ec0d459e0d" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_019f3d68-eb5d-74ea-b1d7-6e01292896cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermAxis_019f3d68-eb5d-756d-96a2-4fc4735676fe" 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_019f3d68-eb5d-7872-8d62-9214bd892428" xlink:to="loc_us-gaap_LeaseContractualTermAxis_019f3d68-eb5d-756d-96a2-4fc4735676fe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_019f3d68-eb5d-756d-96a2-4fc4735676fe_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_019f3d68-eb5d-756d-96a2-4fc4735676fe" xlink:to="loc_us-gaap_LeaseContractualTermDomain_019f3d68-eb5d-756d-96a2-4fc4735676fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LeaseContractualTermDomain_019f3d68-eb5d-7864-bdac-c3278c5baf88" 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_019f3d68-eb5d-756d-96a2-4fc4735676fe" xlink:to="loc_us-gaap_LeaseContractualTermDomain_019f3d68-eb5d-7864-bdac-c3278c5baf88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubleaseIncome_019f3d68-eb5d-7978-aade-0155a2a0d577" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_SubleaseIncome_019f3d68-eb5d-7978-aade-0155a2a0d577" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseRightOfUseAsset_019f3d68-eb5d-78b6-8126-1080f2c9f8bd" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_OperatingLeaseRightOfUseAsset_019f3d68-eb5d-78b6-8126-1080f2c9f8bd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019f3d68-eb5d-7260-adbf-e078182e9352" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_019f3d68-eb5d-7260-adbf-e078182e9352" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalLeaseObligationsIncurred_019f3d68-eb5d-7726-8241-beabcab2b058" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_CapitalLeaseObligationsIncurred_019f3d68-eb5d-7726-8241-beabcab2b058" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_LeaseSquareFootage_019f3d68-eb5d-7777-b8e1-26e0910fd02b" xlink:href="whg-20260630.xsd#whg_LeaseSquareFootage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_whg_LeaseSquareFootage_019f3d68-eb5d-7777-b8e1-26e0910fd02b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Corporateofficesremainingleaseterms_019f3d68-eb5d-7ca8-955e-96a3822e1d5d" xlink:href="whg-20260630.xsd#whg_Corporateofficesremainingleaseterms"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LesseeLeaseDescriptionLineItems_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_whg_Corporateofficesremainingleaseterms_019f3d68-eb5d-7ca8-955e-96a3822e1d5d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LesseeOperatingLeaseTermOfContract_019f3d68-eb5d-742f-93cf-0f270c480a80" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_LesseeOperatingLeaseTermOfContract_019f3d68-eb5d-742f-93cf-0f270c480a80" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandSubjectToGroundLeases_019f3d68-eb5d-7bd0-880d-997d59318708" 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_019f3d68-eb5d-7545-b8de-14fb6df86ef4" xlink:to="loc_us-gaap_LandSubjectToGroundLeases_019f3d68-eb5d-7bd0-880d-997d59318708" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SEGMENTREPORTINGDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" 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_019f3d68-eb5d-7526-8f63-31e29b478558" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019f3d68-eb5d-7526-8f63-31e29b478558" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7369-8574-fb86f8f307c5" 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_019f3d68-eb5d-7526-8f63-31e29b478558" xlink:to="loc_us-gaap_AwardTypeAxis_019f3d68-eb5d-7369-8574-fb86f8f307c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7369-8574-fb86f8f307c5_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_019f3d68-eb5d-7369-8574-fb86f8f307c5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7369-8574-fb86f8f307c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7a26-a1bf-eeb670d69052" 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_019f3d68-eb5d-7369-8574-fb86f8f307c5" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_019f3d68-eb5d-7a26-a1bf-eeb670d69052" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7cac-964c-49ae0ae428c1" 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_019f3d68-eb5d-7a26-a1bf-eeb670d69052" xlink:to="loc_us-gaap_RestrictedStockMember_019f3d68-eb5d-7cac-964c-49ae0ae428c1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_019f3d68-eb5d-7446-b680-cedfc53be599" 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_019f3d68-eb5d-7526-8f63-31e29b478558" xlink:to="loc_srt_ConsolidationItemsAxis_019f3d68-eb5d-7446-b680-cedfc53be599" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f3d68-eb5d-7446-b680-cedfc53be599_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_019f3d68-eb5d-7446-b680-cedfc53be599" xlink:to="loc_srt_ConsolidationItemsDomain_019f3d68-eb5d-7446-b680-cedfc53be599_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_019f3d68-eb5d-7d6c-9448-f52b63f47812" 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_019f3d68-eb5d-7446-b680-cedfc53be599" xlink:to="loc_srt_ConsolidationItemsDomain_019f3d68-eb5d-7d6c-9448-f52b63f47812" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_019f3d68-eb5d-7ab0-8cef-22d60565df0a" 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_019f3d68-eb5d-7d6c-9448-f52b63f47812" xlink:to="loc_us-gaap_OperatingSegmentsMember_019f3d68-eb5d-7ab0-8cef-22d60565df0a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019f3d68-eb5d-76b3-afcb-fecab68706a9" 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_019f3d68-eb5d-7d6c-9448-f52b63f47812" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019f3d68-eb5d-76b3-afcb-fecab68706a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019f3d68-eb5d-7c5e-a685-b6ccc261de7a" 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_019f3d68-eb5d-7d6c-9448-f52b63f47812" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019f3d68-eb5d-7c5e-a685-b6ccc261de7a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-7ed9-b402-776771d1dba3" 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_019f3d68-eb5d-7526-8f63-31e29b478558" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019f3d68-eb5d-7ed9-b402-776771d1dba3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7ed9-b402-776771d1dba3_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_019f3d68-eb5d-7ed9-b402-776771d1dba3" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7ed9-b402-776771d1dba3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7daa-8d8e-797461ff0063" 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_019f3d68-eb5d-7ed9-b402-776771d1dba3" xlink:to="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7daa-8d8e-797461ff0063" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_AdvisoryMember_019f3d68-eb5d-7a77-98aa-69a0a8e18ab0" xlink:href="whg-20260630.xsd#whg_AdvisoryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7daa-8d8e-797461ff0063" xlink:to="loc_whg_AdvisoryMember_019f3d68-eb5d-7a77-98aa-69a0a8e18ab0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustMember_019f3d68-eb5d-78c1-b7b7-3d8d0b021f16" xlink:href="whg-20260630.xsd#whg_TrustMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019f3d68-eb5d-7daa-8d8e-797461ff0063" xlink:to="loc_whg_TrustMember_019f3d68-eb5d-78c1-b7b7-3d8d0b021f16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CorporateNonSegmentMember_019f3d68-eb5d-7472-b42d-cbd336559869" 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_019f3d68-eb5d-7daa-8d8e-797461ff0063" xlink:to="loc_us-gaap_CorporateNonSegmentMember_019f3d68-eb5d-7472-b42d-cbd336559869" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_019f3d68-eb5d-7380-a788-03d85f3a59cd" 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_019f3d68-eb5d-7daa-8d8e-797461ff0063" xlink:to="loc_us-gaap_IntersegmentEliminationMember_019f3d68-eb5d-7380-a788-03d85f3a59cd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7ded-a397-3294d8b5c199" 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_ScheduleOfSegmentReportingInformationBySegmentTable_019f3d68-eb5d-7526-8f63-31e29b478558" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019f3d68-eb5d-7ded-a397-3294d8b5c199" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7ded-a397-3294d8b5c199_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_019f3d68-eb5d-7ded-a397-3294d8b5c199" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-7ded-a397-3294d8b5c199_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" 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_019f3d68-eb5d-7ded-a397-3294d8b5c199" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodFundsMember_019f3d68-eb5d-7049-a0f6-283697754efd" xlink:href="whg-20260630.xsd#whg_WestwoodFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_WestwoodFundsMember_019f3d68-eb5d-7049-a0f6-283697754efd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7242-9a2d-07c8647929f0" xlink:href="whg-20260630.xsd#whg_CommonTrustFundsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_CommonTrustFundsMember_019f3d68-eb5d-7242-9a2d-07c8647929f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_WestwoodHospitalityFundILLCMember_019f3d68-eb5d-7025-ad56-78e35f5e733c" xlink:href="whg-20260630.xsd#whg_WestwoodHospitalityFundILLCMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_WestwoodHospitalityFundILLCMember_019f3d68-eb5d-7025-ad56-78e35f5e733c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-758b-975c-6ffb9c4c0285" xlink:href="whg-20260630.xsd#whg_PrivateEquityInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_PrivateEquityInvestmentsMember_019f3d68-eb5d-758b-975c-6ffb9c4c0285" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PrivateWealthMember_019f3d68-eb5d-7b60-b136-8b5df22e765c" xlink:href="whg-20260630.xsd#whg_PrivateWealthMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_PrivateWealthMember_019f3d68-eb5d-7b60-b136-8b5df22e765c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_InstitutionalMember_019f3d68-eb5d-7934-b9d2-e02048883a4e" xlink:href="whg-20260630.xsd#whg_InstitutionalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019f3d68-eb5d-73da-b9d3-fb455f855a7f" xlink:to="loc_whg_InstitutionalMember_019f3d68-eb5d-7934-b9d2-e02048883a4e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RevenueFromExternalSources_019f3d68-eb5d-7f1b-8fa4-1723ec96a4ff" xlink:href="whg-20260630.xsd#whg_RevenueFromExternalSources"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_whg_RevenueFromExternalSources_019f3d68-eb5d-7f1b-8fa4-1723ec96a4ff" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_NetIntersegmentRevenues_019f3d68-eb5d-7f87-ad0b-083a6a0142a6" xlink:href="whg-20260630.xsd#whg_NetIntersegmentRevenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_whg_NetIntersegmentRevenues_019f3d68-eb5d-7f87-ad0b-083a6a0142a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentIncomeNet_019f3d68-eb5d-7214-aad0-d897691738b5" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_InvestmentIncomeNet_019f3d68-eb5d-7214-aad0-d897691738b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_Otherrevenue_019f3d68-eb5d-77f4-a264-c6e3870a7e1b" xlink:href="whg-20260630.xsd#whg_Otherrevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_whg_Otherrevenue_019f3d68-eb5d-77f4-a264-c6e3870a7e1b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019f3d68-eb5d-7489-a41c-8eebd0f8249d" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_Revenues_019f3d68-eb5d-7489-a41c-8eebd0f8249d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019f3d68-eb5d-78d3-b249-d954950fc56d" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_Assets_019f3d68-eb5d-78d3-b249-d954950fc56d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_019f3d68-eb5d-726a-a167-cf15ed5ff27f" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_Goodwill_019f3d68-eb5d-726a-a167-cf15ed5ff27f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_019f3d68-eb5d-7695-9f4f-aadfdce943ca" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_EquityMethodInvestments_019f3d68-eb5d-7695-9f4f-aadfdce943ca" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019f3d68-eb5d-7a2c-9698-5c9888782af3" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_019f3d68-eb5d-7a2c-9698-5c9888782af3" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeInterestEarningAsset_019f3d68-eb5d-7c17-8dfd-dfb65be6f90b" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_InterestIncomeInterestEarningAsset_019f3d68-eb5d-7c17-8dfd-dfb65be6f90b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019f3d68-eb5d-730c-a8bf-0b7ce284f219" 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_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_NetIncomeLoss_019f3d68-eb5d-730c-a8bf-0b7ce284f219" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019fcf64-392a-70ca-8f0c-78a28ec63e14" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_SegmentExpenditureAdditionToLongLivedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_SegmentExpenditureAdditionToLongLivedAssets_019fcf64-392a-70ca-8f0c-78a28ec63e14" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetsUnderManagementCarryingAmount_019f3d68-eb5d-72d9-903b-7faad72c25a5" 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_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_AssetsUnderManagementCarryingAmount_019f3d68-eb5d-72d9-903b-7faad72c25a5" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradingSecurities_019f3d68-eb5d-72e7-a305-fb46cc552df2" 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_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_us-gaap_TradingSecurities_019f3d68-eb5d-72e7-a305-fb46cc552df2" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_RiskOfLoss_019f3d68-eb5d-727f-8422-04a81f8a4314" xlink:href="whg-20260630.xsd#whg_RiskOfLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019f3d68-eb5d-7ebe-86a8-8f551b86b045" xlink:to="loc_whg_RiskOfLoss_019f3d68-eb5d-727f-8422-04a81f8a4314" xlink:type="arc" order="14"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/SUBSEQUENTEVENTSDetailsTextual" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" 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_019f3d68-eb5d-719e-bd40-39aa975c426f" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_SubsequentEventTable_019f3d68-eb5d-719e-bd40-39aa975c426f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_019f3d68-eb5d-76ec-af1e-2222eb0651dd" 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_019f3d68-eb5d-719e-bd40-39aa975c426f" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_019f3d68-eb5d-76ec-af1e-2222eb0651dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-76ec-af1e-2222eb0651dd_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_019f3d68-eb5d-76ec-af1e-2222eb0651dd" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-76ec-af1e-2222eb0651dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7c5e-882a-9d6c8ffbf65a" 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_019f3d68-eb5d-76ec-af1e-2222eb0651dd" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_019f3d68-eb5d-7c5e-882a-9d6c8ffbf65a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_019f3d68-eb5d-7030-8de3-8d1fa267da47" 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_019f3d68-eb5d-7c5e-882a-9d6c8ffbf65a" xlink:to="loc_us-gaap_SubsequentEventMember_019f3d68-eb5d-7030-8de3-8d1fa267da47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_019f3d68-eb5d-722f-b7a1-bc125da5cbda" 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_019f3d68-eb5d-719e-bd40-39aa975c426f" xlink:to="loc_srt_ProductOrServiceAxis_019f3d68-eb5d-722f-b7a1-bc125da5cbda" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-722f-b7a1-bc125da5cbda_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_019f3d68-eb5d-722f-b7a1-bc125da5cbda" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-722f-b7a1-bc125da5cbda_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7bd8-a44b-b8b50022c8c6" 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_019f3d68-eb5d-722f-b7a1-bc125da5cbda" xlink:to="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7bd8-a44b-b8b50022c8c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_TrustPerformanceBasedFeesMember_019f3d68-eb5d-7f00-9816-fa362c3cc5bb" xlink:href="whg-20260630.xsd#whg_TrustPerformanceBasedFeesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_019f3d68-eb5d-7bd8-a44b-b8b50022c8c6" xlink:to="loc_whg_TrustPerformanceBasedFeesMember_019f3d68-eb5d-7f00-9816-fa362c3cc5bb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f3d68-eb5d-7d06-b2f2-534fab384b55" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_CommonStockDividendsPerShareDeclared_019f3d68-eb5d-7d06-b2f2-534fab384b55" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_019f3d68-eb5d-74e3-beef-a60afbd4e23a" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_DividendPayableDateToBePaidDayMonthAndYear_019f3d68-eb5d-74e3-beef-a60afbd4e23a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_019f3d68-eb5d-797f-9b5b-f54fcd381035" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_DividendsPayableDateOfRecordDayMonthAndYear_019f3d68-eb5d-797f-9b5b-f54fcd381035" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodShares_019f3d68-eb5d-7125-b59e-09ef2cf3ac8d" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodShares_019f3d68-eb5d-7125-b59e-09ef2cf3ac8d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchasedDuringPeriodValue_019f3d68-eb5d-71cb-bab1-5ed8d70edd81" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_StockRepurchasedDuringPeriodValue_019f3d68-eb5d-71cb-bab1-5ed8d70edd81" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019f3d68-eb5d-7b1f-b2d8-86f84bd6035e" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_srt_StockRepurchaseProgramAuthorizedAmount1_019f3d68-eb5d-7b1f-b2d8-86f84bd6035e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019f3d68-eb5d-741f-a1ca-78caa856631d" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_StockRepurchaseProgramRemainingAuthorizedRepurchaseAmount1_019f3d68-eb5d-741f-a1ca-78caa856631d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_StockRepurchaseProgram_019f3d68-eb5d-7788-a110-1fe176490287" xlink:href="whg-20260630.xsd#whg_StockRepurchaseProgram"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_whg_StockRepurchaseProgram_019f3d68-eb5d-7788-a110-1fe176490287" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_StockRepurchaseAuthorizationSubsequentEvent_019f3d68-eb5d-7d55-acc0-2554ccc55980" xlink:href="whg-20260630.xsd#whg_StockRepurchaseAuthorizationSubsequentEvent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_whg_StockRepurchaseAuthorizationSubsequentEvent_019f3d68-eb5d-7d55-acc0-2554ccc55980" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventDescription_019f3d68-eb5d-763f-817f-fc10be80dddf" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_SubsequentEventDescription_019f3d68-eb5d-763f-817f-fc10be80dddf" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019f3d68-eb5d-7658-8e77-f9379460019a" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_019f3d68-eb5d-7658-8e77-f9379460019a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_019f3d68-eb5d-7476-8d58-f6292c8d9e97" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_InvestmentsAllOtherInvestmentsAbstract_019f3d68-eb5d-7476-8d58-f6292c8d9e97" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestInJointVentures_019f3d68-eb5d-7cda-9168-6b7ad99a946a" 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_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_MinorityInterestInJointVentures_019f3d68-eb5d-7cda-9168-6b7ad99a946a" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019f3d68-eb5d-7f64-9c6a-63540532b257" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyAccrualAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_LossContingencyAccrualAtCarryingValue_019f3d68-eb5d-7f64-9c6a-63540532b257" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyReceivable_019f3d68-eb5d-759b-a62a-077dbf920f04" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LossContingencyReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_LossContingencyReceivable_019f3d68-eb5d-759b-a62a-077dbf920f04" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansAndLeasesReceivableGrossCarryingAmount_019f3d68-eb5d-7010-8fda-f693fb1f437f" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansAndLeasesReceivableGrossCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_LoansAndLeasesReceivableGrossCarryingAmount_019f3d68-eb5d-7010-8fda-f693fb1f437f" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LoansReceivableWithFixedRatesOfInterest1_019f3d68-eb5d-7b46-884f-3f3494954679" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_LoansReceivableWithFixedRatesOfInterest1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_LoansReceivableWithFixedRatesOfInterest1_019f3d68-eb5d-7b46-884f-3f3494954679" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentInterestRate_019f3d68-eb5d-75a7-a099-07ac5b423c6b" xlink:href="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd#us-gaap_InvestmentInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventLineItems_019f3d68-eb5d-7c2b-b2c6-0509a6f680d2" xlink:to="loc_us-gaap_InvestmentInterestRate_019f3d68-eb5d-75a7-a099-07ac5b423c6b" xlink:type="arc" order="17"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://westwoodgroup.com/role/BusinessCombinationsandAssetAcquisitionsDetails" xlink:type="simple" xlink:href="whg-20260630.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_019f3d68-ec0a-710c-99e9-e1b786d500cf" 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_019f3d68-ec0a-7448-bbd5-514f6e495134" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_AssetAcquisitionTable_019f3d68-ec0a-7448-bbd5-514f6e495134" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByAssetClassAxis_019f3d68-ec0a-701f-ab5b-ec76ab9e622b" 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_019f3d68-ec0a-7448-bbd5-514f6e495134" xlink:to="loc_us-gaap_FairValueByAssetClassAxis_019f3d68-ec0a-701f-ab5b-ec76ab9e622b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019f3d68-ec0a-701f-ab5b-ec76ab9e622b_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_019f3d68-ec0a-701f-ab5b-ec76ab9e622b" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019f3d68-ec0a-701f-ab5b-ec76ab9e622b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019f3d68-ec0a-702d-862e-293883e43688" 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_019f3d68-ec0a-701f-ab5b-ec76ab9e622b" xlink:to="loc_us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_019f3d68-ec0a-702d-862e-293883e43688" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_019f3d68-ec0a-74a6-a6ef-716f4e4014f1" 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_019f3d68-ec0a-702d-862e-293883e43688" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_019f3d68-ec0a-74a6-a6ef-716f4e4014f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableMember_019f3d68-ec0a-77a5-b804-cf7a984fb122" 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_019f3d68-ec0a-702d-862e-293883e43688" xlink:to="loc_us-gaap_AccountsReceivableMember_019f3d68-ec0a-77a5-b804-cf7a984fb122" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentMember_019f3d68-ec0a-79ca-b38a-c1570fecb803" 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_019f3d68-ec0a-702d-862e-293883e43688" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentMember_019f3d68-ec0a-79ca-b38a-c1570fecb803" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAssetsMember_019f3d68-ec0a-7a91-acd8-60b8c6046e5d" 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_019f3d68-ec0a-702d-862e-293883e43688" xlink:to="loc_us-gaap_OtherAssetsMember_019f3d68-ec0a-7a91-acd8-60b8c6046e5d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f3d68-ec0a-70e6-9d7b-db746edb064e" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_019f3d68-ec0a-70e6-9d7b-db746edb064e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019f3d68-ec0a-78d9-80ea-51e25f45829f" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaRevenue_019f3d68-ec0a-78d9-80ea-51e25f45829f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019f3d68-ec0a-7573-a5d3-275fec0ca825" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessAcquisitionsProFormaNetIncomeLoss_019f3d68-ec0a-7573-a5d3-275fec0ca825" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription_019f3d68-ec0a-7b6d-89ae-a470288eb612" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessCombinationStepAcquisitionEquityInterestInAcquireeDescription_019f3d68-ec0a-7b6d-89ae-a470288eb612" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_019f3d68-ec0a-7d0f-9972-7201f344539e" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual_019f3d68-ec0a-7d0f-9972-7201f344539e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_019f3d68-ec0a-779b-addb-30ae58ac8f61" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual_019f3d68-ec0a-779b-addb-30ae58ac8f61" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest_019f3d68-ec0a-77a4-8918-a3b390361e89" xlink:href="whg-20260630.xsd#whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_whg_BusinessCombinationAcquisitionOfLessThan100PercentOfBroadmarkNoncontontrollingInterest_019f3d68-ec0a-77a4-8918-a3b390361e89" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_BusinessCombinationConsiderationTransferredForBroadmark_019f3d68-ec0a-7259-945f-abc0027acc74" xlink:href="whg-20260630.xsd#whg_BusinessCombinationConsiderationTransferredForBroadmark"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_whg_BusinessCombinationConsiderationTransferredForBroadmark_019f3d68-ec0a-7259-945f-abc0027acc74" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_whg_PaymentsToAcquireBroadmarkGross_019f3d68-ec0a-79aa-a42f-bd42297afcd2" xlink:href="whg-20260630.xsd#whg_PaymentsToAcquireBroadmarkGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AssetAcquisitionLineItems_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_whg_PaymentsToAcquireBroadmarkGross_019f3d68-ec0a-79aa-a42f-bd42297afcd2" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019f3d68-ec0a-7409-a0a6-fcc7220d337c" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_MinorityInterestOwnershipPercentageByParent_019f3d68-ec0a-7409-a0a6-fcc7220d337c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019f3d68-ec0a-7978-a91c-609efb1b6e1d" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityFinancingActivities_019f3d68-ec0a-7978-a91c-609efb1b6e1d" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_019f3d68-ec0a-75da-b83d-aa4dc967e3ba" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityOperatingActivities_019f3d68-ec0a-75da-b83d-aa4dc967e3ba" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_019f3d68-ec0a-76cf-a691-39ec71a8e7ba" 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_019f3d68-ec0a-710c-99e9-e1b786d500cf" xlink:to="loc_us-gaap_PaymentForContingentConsiderationLiabilityInvestingActivities_019f3d68-ec0a-76cf-a691-39ec71a8e7ba" xlink:type="arc" order="12"/>
  </link:definitionLink>
</link:linkbase>
