<SEC-DOCUMENT>0001243729-19-000002.txt : 20190122
<SEC-HEADER>0001243729-19-000002.hdr.sgml : 20190122
<ACCEPTANCE-DATETIME>20190122164905
ACCESSION NUMBER:		0001243729-19-000002
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:			ROSENTHAL ROBERT
		CENTRAL INDEX KEY:			0001243729

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13792
		FILM NUMBER:		19535779

	MAIL ADDRESS:	
		STREET 1:		C/O SYSTEMAX INC.
		STREET 2:		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_154819372901180.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>0001243729</rptOwnerCik>
            <rptOwnerName>ROSENTHAL ROBERT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SYSTEMAX INC., 11 HARBOR PARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PORT WASHINGTON</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11050</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>7.85</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>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-10-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.55</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>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-10-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>10000.0</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</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 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 Stock Option (right to buy). The Option Repricing was related to a special dividend declared in December 2018.</footnote>
        <footnote id="F2">The Stock Option (right to buy) granted on October 31, 2016  vested in three installments: 3,334 shares on October 31, 2017; 3,333 shares on October 31, 2018 and 3,333 shares October 31, 2019.</footnote>
    </footnotes>

    <remarks></remarks>

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