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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-03-26</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001419581</issuerCik>
        <issuerName>Federal-Mogul Holdings Corp</issuerName>
        <issuerTradingSymbol>FDML</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000921669</rptOwnerCik>
            <rptOwnerName>ICAHN CARL C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ICAHN ASSOCIATES HOLDING LLC</rptOwnerStreet1>
            <rptOwnerStreet2>767 FIFTH AVE., SUITE 4700</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10153</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <officerTitle></officerTitle>
            <otherText>Non-exec. BOD Chair.: FNs 1-4</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share (&quot;Shares&quot;)</value>
            </securityTitle>
            <transactionDate>
                <value>2015-03-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>X</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>17478165</value>
                    <footnoteId id="F5"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.15</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>138590141</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>please see footnotes 1 through 4</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Subscription Rights (&quot;right to buy&quot;)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.15</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-03-26</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>X</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>121111976</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2015-03-06</value>
            </exerciseDate>
            <expirationDate>
                <value>2015-03-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Shares</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17478165</value>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>please see footnotes 1 through 4</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">IEH FM Holdings LLC (&quot;FM Holdings&quot;) directly beneficially owns 138,590,141 Shares. American Entertainment Properties Corp. (&quot;AEP&quot;) is the sole member of FM Holdings. Icahn Building LLC (&quot;Icahn Building&quot;) is the sole stockholder of AEP. Icahn Enterprises Holdings L.P. (&quot;Icahn Enterprises Holdings&quot;) is the sole member of Icahn Building. Icahn Enterprises G.P. Inc. (&quot;Icahn Enterprises GP&quot;) is the general partner of Icahn Enterprises Holdings. Beckton Corp. (&quot;Beckton&quot;) is the sole stockholder of Icahn Enterprises GP.</footnote>
        <footnote id="F2">Beckton is 100 percent owned by Carl C. Icahn. As such, Mr. Icahn is in a position indirectly to determine the investment and voting decisions made by each of the foregoing entities. In addition, Mr. Icahn is the indirect holder of approximately 89.3% of the outstanding depositary units representing limited partnership interests in Icahn Enterprises L.P. (&quot;Icahn Enterprises&quot;). Icahn Enterprises GP is the general partner of Icahn Enterprises, which is the sole limited partner of Icahn Enterprises Holdings.</footnote>
        <footnote id="F3">Each of AEP, Icahn Building, Icahn Enterprises Holdings, Icahn Enterprises GP and Beckton (by virtue of their relationship to FM Holdings) and Mr. Icahn (by virtue of his relationship to Beckton), may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under the Act) the Shares which FM Holdings owns. Each of AEP, Icahn Building, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton and Mr. Icahn disclaims beneficial ownership of such Shares except to the extent of their pecuniary interest therein.</footnote>
        <footnote id="F4">Does not include 34,798 Shares owned by Gail Golden, the spouse of Mr. Icahn. Mr. Icahn, by virtue of his relationship to Ms. Golden, may be deemed to beneficially own such Shares. Mr. Icahn disclaims beneficial ownership of such Shares for all purposes.</footnote>
        <footnote id="F5">Represents Shares acquired upon exercise of basic subscription rights and oversubscription rights allocated to FM Holdings in the rights offering conducted by the Issuer, which expired on March 23, 2015. The acquisition of the subscription rights by FM Holdings was exempt from Section 16 by virtue of Rule 16a-9(b) and the purchase of Shares by FM Holdings pursuant to the exercise of the subscription rights was exempt from Section 16(b) by virtue of Section 16b-6(b).</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>CARL C. ICAHN</signatureName>
        <signatureDate>2015-03-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
