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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2015-06-24</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001637913</issuerCik>
        <issuerName>Milacron Holdings Corp.</issuerName>
        <issuerTradingSymbol>MCRN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001559142</rptOwnerCik>
            <rptOwnerName>Kratochvil Jim M.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MILACRON HOLDINGS CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>3010 DISNEY STREET</rptOwnerStreet2>
            <rptOwnerCity>CINCINNATTI</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>45209</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>55400</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Of the shares reported as beneficially owned, 2,250 are restricted stock units that represent the right to receive, at settlement, one (1) share of common stock, and which are subject to vesting and forfeiture. Prior to vesting, the restricted stock units do not include any voting rights.</footnote>
    </footnotes>

    <remarks>See Exhibit 24.1 - Power of Attorney.</remarks>

    <ownerSignature>
        <signatureName>/s/ Hugh O'Donnell, as Attorney-in-Fact for James M. Kratochvil</signatureName>
        <signatureDate>2015-06-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
