<SEC-DOCUMENT>0000927628-21-000062.txt : 20210216
<SEC-HEADER>0000927628-21-000062.hdr.sgml : 20210216
<ACCEPTANCE-DATETIME>20210216181824
ACCESSION NUMBER:		0000927628-21-000062
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210204
FILED AS OF DATE:		20210216
DATE AS OF CHANGE:		20210216

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Golden Timothy P
		CENTRAL INDEX KEY:			0001706865

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13300
		FILM NUMBER:		21641617

	MAIL ADDRESS:	
		STREET 1:		1680 CAPITAL ONE DRIVE
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22102

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CAPITAL ONE FINANCIAL CORP
		CENTRAL INDEX KEY:			0000927628
		STANDARD INDUSTRIAL CLASSIFICATION:	NATIONAL COMMERCIAL BANKS [6021]
		IRS NUMBER:				541719854
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1680 CAPITAL ONE DRIVE
		STREET 2:		SUITE 1400
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22102
		BUSINESS PHONE:		7037201000

	MAIL ADDRESS:	
		STREET 1:		1680 CAPITAL ONE DRIVE
		STREET 2:		SUITE 1400
		CITY:			MCLEAN
		STATE:			VA
		ZIP:			22102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OAKSTONE FINANCIAL CORP
		DATE OF NAME CHANGE:	19940728
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>wf-form4a_161351747066901.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2021-02-04</periodOfReport>

    <dateOfOriginalSubmission>2021-02-08</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000927628</issuerCik>
        <issuerName>CAPITAL ONE FINANCIAL CORP</issuerName>
        <issuerTradingSymbol>COF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001706865</rptOwnerCik>
            <rptOwnerName>Golden Timothy P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1680 CAPITAL ONE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MCLEAN</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22102</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Controller</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2021-02-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8367</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16184</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These restricted stock unit awards will vest in 1/3 increments beginning on February 15, 2022 and annually thereafter. Each restricted stock unit represents a contingent right to receive one share of Company common stock.</footnote>
        <footnote id="F2">One of the restricted stock unit awards representing 4,439 shares of Company common stock was not previously reported due to an administrative reporting error.</footnote>
        <footnote id="F3">Includes shares acquired by the reporting person through the Company's Associate Stock Purchase Plan since the last reported transaction.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Cleo Belmonte (POA on file)</signatureName>
        <signatureDate>2021-02-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
