<SEC-DOCUMENT>0000034782-17-000004.txt : 20170131
<SEC-HEADER>0000034782-17-000004.hdr.sgml : 20170131
<ACCEPTANCE-DATETIME>20170131151933
ACCESSION NUMBER:		0000034782-17-000004
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170124
FILED AS OF DATE:		20170131
DATE AS OF CHANGE:		20170131

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:			Buhr Jeffrey L
		CENTRAL INDEX KEY:			0001599829

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-06233
		FILM NUMBER:		17560860

	MAIL ADDRESS:	
		STREET 1:		PO BOX 1602
		CITY:			SOUTH BEND
		STATE:			IN
		ZIP:			46634
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_148589396020486.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-01-24</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001599829</rptOwnerCik>
            <rptOwnerName>Buhr Jeffrey L</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>Executive Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-01-24</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>46</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>47933</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4121</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Between January 1, 2016 and December 31, 2016, Mr. Buhr acquired 223 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>2017-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
