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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:01a1792d-f854-745e-9889-79a62bcaff10,g:0a2fc550-0cd8-451d-b507-8217f3a16e11-->
<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://www.centrusenergy.com/role/Cover" xlink:type="simple" xlink:href="leu-20261029.xsd#Cover"/>
  <link:definitionLink xlink:role="http://www.centrusenergy.com/role/Cover" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationTable_01a1792d-f854-70b9-8358-69d37fe1242a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_DocumentInformationTable_01a1792d-f854-70b9-8358-69d37fe1242a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentInformationDocumentAxis_01a1792d-f854-7e7c-8502-798f65f8c905" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentInformationDocumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_dei_DocumentInformationTable_01a1792d-f854-70b9-8358-69d37fe1242a" xlink:to="loc_dei_DocumentInformationDocumentAxis_01a1792d-f854-7e7c-8502-798f65f8c905" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_01a1792d-f854-7e7c-8502-798f65f8c905_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_DocumentInformationDocumentAxis_01a1792d-f854-7e7c-8502-798f65f8c905" xlink:to="loc_dei_DocumentDomain_01a1792d-f854-7e7c-8502-798f65f8c905_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentDomain_01a1792d-f854-7e06-8c72-8b1af8059b4b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_DocumentInformationDocumentAxis_01a1792d-f854-7e7c-8502-798f65f8c905" xlink:to="loc_dei_DocumentDomain_01a1792d-f854-7e06-8c72-8b1af8059b4b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityCentralIndexKey_01a1792d-f854-7a95-8859-edfc07d6acd4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityCentralIndexKey"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityCentralIndexKey_01a1792d-f854-7a95-8859-edfc07d6acd4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_AmendmentFlag_01a1792d-f854-7282-af9b-7270fd1ef158" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_AmendmentFlag"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_AmendmentFlag_01a1792d-f854-7282-af9b-7270fd1ef158" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityRegistrantName_01a1792d-f854-72cd-be39-0f718d137ec8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityRegistrantName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityRegistrantName_01a1792d-f854-72cd-be39-0f718d137ec8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentPeriodEndDate_01a1792d-f854-7e1e-846b-a6c6b126bb66" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentPeriodEndDate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_DocumentPeriodEndDate_01a1792d-f854-7e1e-846b-a6c6b126bb66" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_DocumentType_01a1792d-f854-792b-b43d-4fb90d2a9f64" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_DocumentType"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_DocumentType_01a1792d-f854-792b-b43d-4fb90d2a9f64" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine1_01a1792d-f854-7134-be87-b03e7c475b54" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityAddressAddressLine1_01a1792d-f854-7134-be87-b03e7c475b54" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressAddressLine2_01a1792d-f854-7161-822b-909e846bda52" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressAddressLine2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityAddressAddressLine2_01a1792d-f854-7161-822b-909e846bda52" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressCityOrTown_01a1792d-f854-70de-bd23-37c86307da7b" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressCityOrTown"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityAddressCityOrTown_01a1792d-f854-70de-bd23-37c86307da7b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressStateOrProvince_01a1792d-f854-7b63-8196-e06629a2f6f5" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressStateOrProvince"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityAddressStateOrProvince_01a1792d-f854-7b63-8196-e06629a2f6f5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityAddressPostalZipCode_01a1792d-f854-7542-9175-70f13e0d94bb" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityAddressPostalZipCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityAddressPostalZipCode_01a1792d-f854-7542-9175-70f13e0d94bb" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_CityAreaCode_01a1792d-f854-7e19-b735-7d0dbc4367dd" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_CityAreaCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_CityAreaCode_01a1792d-f854-7e19-b735-7d0dbc4367dd" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LocalPhoneNumber_01a1792d-f854-791f-b21b-61cc5698a4be" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LocalPhoneNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_LocalPhoneNumber_01a1792d-f854-791f-b21b-61cc5698a4be" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityEmergingGrowthCompany_01a1792d-f854-7b07-82f5-20fb52ee4b74" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityEmergingGrowthCompany"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityEmergingGrowthCompany_01a1792d-f854-7b07-82f5-20fb52ee4b74" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityFileNumber_01a1792d-f854-75ed-b286-5496e7676c82" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityFileNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityFileNumber_01a1792d-f854-75ed-b286-5496e7676c82" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityIncorporationStateCountryCode_01a1792d-f854-7bdb-ae95-500817460b2e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityIncorporationStateCountryCode"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityIncorporationStateCountryCode_01a1792d-f854-7bdb-ae95-500817460b2e" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityTaxIdentificationNumber_01a1792d-f854-78b8-96f7-92cc3afe08d8" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityTaxIdentificationNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_EntityTaxIdentificationNumber_01a1792d-f854-78b8-96f7-92cc3afe08d8" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_WrittenCommunications_01a1792d-f854-74c4-b8a3-27fb1063ce40" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_WrittenCommunications"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_WrittenCommunications_01a1792d-f854-74c4-b8a3-27fb1063ce40" xlink:type="arc" order="16"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SolicitingMaterial_01a1792d-f854-7ffa-900d-4440a99275a4" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SolicitingMaterial"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_SolicitingMaterial_01a1792d-f854-7ffa-900d-4440a99275a4" xlink:type="arc" order="17"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementTenderOffer_01a1792d-f854-7244-acc0-ead51b718e73" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_PreCommencementTenderOffer_01a1792d-f854-7244-acc0-ead51b718e73" xlink:type="arc" order="18"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_PreCommencementIssuerTenderOffer_01a1792d-f854-76ed-8a90-bb77d7a3423e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_PreCommencementIssuerTenderOffer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_PreCommencementIssuerTenderOffer_01a1792d-f854-76ed-8a90-bb77d7a3423e" xlink:type="arc" order="19"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_Security12bTitle_01a1792d-f854-79ff-9b11-ef0852080b2e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_Security12bTitle"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_Security12bTitle_01a1792d-f854-79ff-9b11-ef0852080b2e" xlink:type="arc" order="20"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_TradingSymbol_01a1792d-f854-7f78-82bc-88ada2c482ef" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_TradingSymbol"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_TradingSymbol_01a1792d-f854-7f78-82bc-88ada2c482ef" xlink:type="arc" order="21"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_SecurityExchangeName_01a1792d-f854-7098-9738-305d7b381d8f" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_SecurityExchangeName"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_DocumentInformationLineItems_01a1792d-f854-7a6a-bef1-f0965a9da522" xlink:to="loc_dei_SecurityExchangeName_01a1792d-f854-7098-9738-305d7b381d8f" xlink:type="arc" order="22"/>
  </link:definitionLink>
</link:linkbase>
