<SEC-DOCUMENT>0001530950-21-000284.txt : 20210902
<SEC-HEADER>0001530950-21-000284.hdr.sgml : 20210902
<ACCEPTANCE-DATETIME>20210902161631
ACCESSION NUMBER:		0001530950-21-000284
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20210831
FILED AS OF DATE:		20210902
DATE AS OF CHANGE:		20210902

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			KEMPER DAVID W
		CENTRAL INDEX KEY:			0000924750

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35305
		FILM NUMBER:		211233435

	MAIL ADDRESS:	
		STREET 1:		PO BOX 419248
		CITY:			KANSAS CITY
		STATE:			MO
		ZIP:			64141-6248

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Post Holdings, Inc.
		CENTRAL INDEX KEY:			0001530950
		STANDARD INDUSTRIAL CLASSIFICATION:	GRAIN MILL PRODUCTS [2040]
		IRS NUMBER:				453355106
		STATE OF INCORPORATION:			MO
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		2503 S. HANLEY ROAD
		CITY:			ST. LOUIS
		STATE:			MO
		ZIP:			63144
		BUSINESS PHONE:		314-644-7600

	MAIL ADDRESS:	
		STREET 1:		2503 S. HANLEY ROAD
		CITY:			ST. LOUIS
		STATE:			MO
		ZIP:			63144
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_163061376093790.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-08-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001530950</issuerCik>
        <issuerName>Post Holdings, Inc.</issuerName>
        <issuerTradingSymbol>POST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000924750</rptOwnerCik>
            <rptOwnerName>KEMPER DAVID W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O POST HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2503 S. HANLEY ROAD</rptOwnerStreet2>
            <rptOwnerCity>ST. LOUIS</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63144</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Post Holdings, Inc. Stock Equivalents</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-08-31</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>109.212</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>111.91</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>109.212</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8292.154</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Reporting Person's retainers earned as a Director of Issuer are deferred into Post Holdings, Inc. stock equivalents under the Issuer's Deferred Compensation Plan for Non-Management Directors. Reporting Person is credited with stock equivalents as soon as administratively practicable following the month in which such retainer is earned.  The value of these stock equivalents is distributed (on a one-for-one basis) in the form of cash upon retirement from the Board of Directors.</footnote>
        <footnote id="F2">The stock equivalents have no fixed exercisable or expiration dates.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Diedre J. Gray, Attorney-in-Fact</signatureName>
        <signatureDate>2021-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
