<SEC-DOCUMENT>0001718653-19-000001.txt : 20190122
<SEC-HEADER>0001718653-19-000001.hdr.sgml : 20190122
<ACCEPTANCE-DATETIME>20190122161100
ACCESSION NUMBER:		0001718653-19-000001
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20190117
FILED AS OF DATE:		20190122
DATE AS OF CHANGE:		20190122

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Kipe David
		CENTRAL INDEX KEY:			0001718653

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13792
		FILM NUMBER:		19535489

	MAIL ADDRESS:	
		STREET 1:		11 HARBOR PARK DRIVE
		CITY:			PORT WASHINGTON
		STATE:			NY
		ZIP:			11050

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SYSTEMAX INC
		CENTRAL INDEX KEY:			0000945114
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-INDUSTRIAL MACHINERY & EQUIPMENT [5084]
		IRS NUMBER:				113262067
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		11 HARBOR PARK DR
		CITY:			PORT WASHINGTON
		STATE:			NY
		ZIP:			11050
		BUSINESS PHONE:		5166087000

	MAIL ADDRESS:	
		STREET 1:		11 HARBOR PARK DRIVE
		CITY:			PORT WASHINGTON
		STATE:			NY
		ZIP:			11050

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	GLOBAL DIRECTMAIL CORP
		DATE OF NAME CHANGE:	19950509
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_154819144339068.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-01-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000945114</issuerCik>
        <issuerName>SYSTEMAX INC</issuerName>
        <issuerTradingSymbol>SYX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001718653</rptOwnerCik>
            <rptOwnerName>Kipe David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SYSTEMAX INC.</rptOwnerStreet1>
            <rptOwnerStreet2>11 HARBOR PARK DRIVE</rptOwnerStreet2>
            <rptOwnerCity>PORT WASHINGTON</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11050</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>SVP &amp; Chief Operations Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.66</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-01-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>17550</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-10-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17550.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Employee Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.36</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-01-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>17550</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2028-10-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17550.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17550</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The transactions reported herein reflect a one-time stock option repricing (the &quot;Option Repricing&quot;) that became effective on January 17, 2019 and are being reported in this manner solely to comply with the technical reporting requirements under Section 16(a) of the Securities Exchange Act of 1934. Pursuant to the Option Repricing, the exercise price of the Employee Stock Option (right to buy) has been amended to reduce such exercise price by $2.30. There have been no other changes to the terms of the Employee Stock Option (right to buy). The Option Repricing was related to a special dividend declared in December 2018.</footnote>
        <footnote id="F2">On October 2, 2018, the reporting person was granted 17,550 stock options pursuant to the Company's 2010 Long Term Incentive Plan, which vest over three years in equal installments of 5,850, starting on February 1, 2020 based on the achievement of a minimum adjusted operating income as determined in a manner consistent with the methods used in the Issuer's regular reports on Form 10K and Form 10Q.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ David Kipe by April Gruder, Attorney-in-Fact</signatureName>
        <signatureDate>2019-01-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
