<SEC-DOCUMENT>0000034782-17-000021.txt : 20170209
<SEC-HEADER>0000034782-17-000021.hdr.sgml : 20170209
<ACCEPTANCE-DATETIME>20170209153821
ACCESSION NUMBER:		0000034782-17-000021
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170208
FILED AS OF DATE:		20170209
DATE AS OF CHANGE:		20170209

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			1ST SOURCE CORP
		CENTRAL INDEX KEY:			0000034782
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				351068133
		STATE OF INCORPORATION:			IN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		100 NORTH MICHIGAN STREET
		CITY:			SOUTH BEND
		STATE:			IN
		ZIP:			46601
		BUSINESS PHONE:		5742352702

	MAIL ADDRESS:	
		STREET 1:		P O BOX 1602
		STREET 2:		P O BOX 1602
		CITY:			SOUTH BEND
		STATE:			IN
		ZIP:			46634

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FBT BANCORP INC
		DATE OF NAME CHANGE:	19820818

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Seitz James R
		CENTRAL INDEX KEY:			0001524978

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06233
		FILM NUMBER:		17587369

	MAIL ADDRESS:	
		STREET 1:		PO BOX 1602
		CITY:			SOUTH BEND
		STATE:			IN
		ZIP:			46634
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148667268788542.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-02-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000034782</issuerCik>
        <issuerName>1ST SOURCE CORP</issuerName>
        <issuerTradingSymbol>SRCE</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001524978</rptOwnerCik>
            <rptOwnerName>Seitz James R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>P.O. BOX 1602</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH BEND</rptOwnerCity>
            <rptOwnerState>IN</rptOwnerState>
            <rptOwnerZipCode>46634</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-02-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3933</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>46151</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22348</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">EIP awards for 2016.</footnote>
        <footnote id="F2">Between January 1, 2016 and December 31, 2016, Mr. Seitz acquired 720 shares of 1st Source Corporation common stock under the 401(k) plan. The information is this report is based on a plan statement dated December 31, 2016.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ John B. Griffith, Attorney-in-Fact</signatureName>
        <signatureDate>2017-02-09</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
