<SEC-DOCUMENT>0000798354-25-000045.txt : 20250210
<SEC-HEADER>0000798354-25-000045.hdr.sgml : 20250210
<ACCEPTANCE-DATETIME>20250210214332
ACCESSION NUMBER:		0000798354-25-000045
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20250207
FILED AS OF DATE:		20250210
DATE AS OF CHANGE:		20250210

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Lyons Michael P.
		CENTRAL INDEX KEY:			0001534574
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-38962
		FILM NUMBER:		25607479

	MAIL ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FISERV INC
		CENTRAL INDEX KEY:			0000798354
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		ORGANIZATION NAME:           	07 Trade & Services
		IRS NUMBER:				391506125
		STATE OF INCORPORATION:			WI
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203
		BUSINESS PHONE:		2628795000

	MAIL ADDRESS:	
		STREET 1:		600 N. VEL R. PHILLIPS AVENUE
		CITY:			MILWAUKEE
		STATE:			WI
		ZIP:			53203
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wk-form4_1739241806.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2025-02-07</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000798354</issuerCik>
        <issuerName>FISERV INC</issuerName>
        <issuerTradingSymbol>FI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001534574</rptOwnerCik>
            <rptOwnerName>Lyons Michael P.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>600 N. VEL R. PHILLIPS AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MILWAUKEE</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>53203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO-Elect</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2025-02-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>42827</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>42827</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Lyons received two separate grants of restricted stock units on February 7, 2025.  The grant of 14,834 restricted stock units will vest in two tranches with 9,725 units vesting on December 31, 2025 and 5,109 units vesting on December 31, 2026. The grant of 27,993 restricted stock units vest one-third on each anniversary of the grant date.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Eric C. Nelson (attorney-in-fact)</signatureName>
        <signatureDate>2025-02-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
