<SEC-DOCUMENT>0001179110-14-001619.txt : 20140131
<SEC-HEADER>0001179110-14-001619.hdr.sgml : 20140131
<ACCEPTANCE-DATETIME>20140131155654
ACCESSION NUMBER:		0001179110-14-001619
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20130130
FILED AS OF DATE:		20140131
DATE AS OF CHANGE:		20140131

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			FASTENAL CO
		CENTRAL INDEX KEY:			0000815556
		STANDARD INDUSTRIAL CLASSIFICATION:	RETAIL-BUILDING MATERIALS, HARDWARE, GARDEN SUPPLY [5200]
		IRS NUMBER:				410948415
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987
		BUSINESS PHONE:		5074545374

	MAIL ADDRESS:	
		STREET 1:		2001 THEURER BLVD
		CITY:			WINONA
		STATE:			MN
		ZIP:			55987

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Ancius Michael J
		CENTRAL INDEX KEY:			0001454708

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-16125
		FILM NUMBER:		14564750

	MAIL ADDRESS:	
		STREET 1:		151 COACHLITE COURT NORTH
		CITY:			ONALASKA
		STATE:			WI
		ZIP:			54650
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-01-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000815556</issuerCik>
        <issuerName>FASTENAL CO</issuerName>
        <issuerTradingSymbol>FAST</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001454708</rptOwnerCik>
            <rptOwnerName>Ancius Michael J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>151 COACHLITE COURT</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ONALASKA</rptOwnerCity>
            <rptOwnerState>WI</rptOwnerState>
            <rptOwnerZipCode>54650</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2014-01-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>120</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>44.297</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>430</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Owned by Son</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6965</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>399</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Held in child custodian account</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Amount held by reporting person's son was erroneously reported on a Form 4 filed on January 28, 2014 as 279 securities and the amount held by reporting person's son should have been reported as 310 securities. After the completing this January 30, 2014 transaction, the reporting person's son owns 430 securities.</footnote>
        <footnote id="F2">Includes 5780 shares held in a revocable trust jointly owned with spouse in which reporting person shares voting and investment power and 1185 shares held in the reporting person's self-directed IRA.</footnote>
        <footnote id="F3">Reporting person disclaims beneficial ownership of these securities and this report shall not be deemed an admission that the reporting person is the beneficial owner of the securities for Section 16 purposes or any other purpose.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John J. Milek, Attorney-in-Fact</signatureName>
        <signatureDate>2014-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
