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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-04-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000908311</issuerCik>
        <issuerName>CIM Commercial Trust Corp</issuerName>
        <issuerTradingSymbol>CMCT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001601806</rptOwnerCik>
            <rptOwnerName>Kuba Shaul</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4700 WILSHIRE BLVD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOS ANGELES</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90010</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-04-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>203349</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.6</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2946448</value>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnotes (3) and (4)</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5204</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote 5</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">CIM Capital, LLC (&quot;CIM Capital&quot;), a wholly owned subsidiary of CIM Group, LLC , received 203,349 shares of common stock from the Issuer as payment for the obligation of CIM Urban Partners, L.P. (&quot;CIM Urban&quot;), a wholly-owned indirect subsidiary of the Issuer, to pay CIM Capital a management fee in respect of the first fiscal quarter of 2020 pursuant to the investment management agreement between CIM Capital and CIM Urban.</footnote>
        <footnote id="F2">All share amounts give effect to the 3-for-1 reverse stock split of the common stock of the Issuer on September 3, 2019.</footnote>
        <footnote id="F3">These shares are owned directly by CIM Service Provider, LLC, CIM Urban Sponsor, LLC and CIM Capital, LLC. CIM Group, LLC is the sole equity member of each of CIM Service Provider, LLC, CIM Urban Sponsor, LLC and CIM Capital, LLC. The reporting person, Avraham Shemesh and Richard Ressler may be deemed to beneficially own all of these shares because of their positions with CIM Group, LLC. The reporting person disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein, and the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.</footnote>
        <footnote id="F4">Includes 2,468,390 shares of common stock of the Issuer acquired by CIM Service Provider, LLC at a price of $19.1685 per share on October 11, 2019 and not previously reported by the reporting person on Form 4, and does not include 13,719,185 shares of common stock previously held by Urban Partners II, LLC (an entity for which the Reporting Person was a controlling person) included in the Reporting Person's prior Form 4 in which he had no pecuniary interest.</footnote>
        <footnote id="F5">Shares held by The Kuba Family Trust of which the reporting person was the grantor and the indirect beneficial owner.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ David Thompson, attorney in fact</signatureName>
        <signatureDate>2020-04-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
