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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2015-09-26</periodOfReport>

    <dateOfOriginalSubmission>2015-09-29</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001641991</issuerCik>
        <issuerName>SPX FLOW, Inc.</issuerName>
        <issuerTradingSymbol>FLOW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001629079</rptOwnerCik>
            <rptOwnerName>Wilson David J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SPX FLOW, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>13320 BALLANTYNE CORPORATE PLACE</rptOwnerStreet2>
            <rptOwnerCity>CHARLOTTE</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>28277</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Pres., Industrial</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-09-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>16921</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24810</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15928</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee stock option to purchase common stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>61.29</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-09-26</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15801</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2025-01-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>15801</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15801</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock and restricted stock units granted in accordance with the employee matters agreement between the Issuer and SPX Corporation (&quot;SPX&quot;) to replace restricted stock and restricted stock units of SPX held by the reporting person immediately prior to the distribution by SPX to its stockholders of all of the outstanding shares of the common stock of the Issuer (the &quot;Spin-off&quot;).</footnote>
        <footnote id="F2">Includes shares of Issuer common stock received in connection with the Spin-off in an exempt transaction pursuant to Rule 16a-9.</footnote>
        <footnote id="F3">Represents options to purchase shares of the Issuer's common stock granted to the reporting person as a result of adjustments to existing SPX stock options made in connection with the Spin-off.</footnote>
        <footnote id="F4">The option vests in three equal annual installments beginning on January 2, 2016, and the exercise period ends on January 2, 2025.</footnote>
    </footnotes>

    <remarks>This amendment to Form 4 is being filed to revise the number of securities beneficially owned by the Reporting Person following the Spin-off reported in the original Form 4 filed on September 29, 2015 due to a recalculation of the relevant conversion rates in respect of restricted stock, restricted stock units and employee stock options following completion of the Spin-off.</remarks>

    <ownerSignature>
        <signatureName>Brian Webb, Attorney In Fact for David J. Wilson</signatureName>
        <signatureDate>2015-10-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
