<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2010-02-09</periodOfReport>

    <dateOfOriginalSubmission>2010-02-10</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000049754</issuerCik>
        <issuerName>DineEquity, Inc</issuerName>
        <issuerTradingSymbol>DIN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001072321</rptOwnerCik>
            <rptOwnerName>STEWART JULIA A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>450 N. BRAND BOULEVARD - FLR 7</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GLENDALE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91203</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-02-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.0155</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>66010</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Julia Stewart Trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>61333</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>563</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">These shares were sold pursuant to a Rule 10b5-1 trading plan established on December 11, 2009. On February 10, 2010, a Form 4 was filed on behalf of the reporting person which inadvertently indicated that these shares were sold directly by the reporting person when the shares were sold by the reporting person's trust, the Julia Stewart Trust. This Form 4 is being filed to amend that Form 4 to reflect the sale of these shares by the Julia Stewart Trust and accordingly adjust the number of shares reported as beneficially owned directly by the reporting person and the Julia Stewart Trust immediately following the transaction reported herein.</footnote>
        <footnote id="F2">This transaction was executed in multiple trades at prices ranging from $25.00 to $25.06. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.</footnote>
        <footnote id="F3">The number of shares reported as beneficially owned by the Julia Stewart Trust immediately following this transaction has been adjusted to reflect the transfer by the reporting person on December 29, 2009 of 63,421 shares of the Issuer's common stock directly owned by the reporting person to the Julia Stewart Trust.</footnote>
        <footnote id="F4">The reporting person is the sole trustee and sole beneficiary of the Julia Stewart Trust.</footnote>
        <footnote id="F5">The number of shares reported as beneficially owned directly by the reporting person has been adjusted to reflect the transfer by the reporting person on December 29, 2009 of 63,421 shares of the Issuer's common stock directly owned by the reporting person to the Julia Stewart Trust for which the reporting person is the sole trustee and sole beneficiary.</footnote>
        <footnote id="F6">These shares are held in the DineEquity, Inc. 401(k) plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Julia A. Stewart</signatureName>
        <signatureDate>2010-02-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
