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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 vYrLtAJmYEshz653iT+ioA==

<SEC-DOCUMENT>0001181431-10-027243.txt : 20100517
<SEC-HEADER>0001181431-10-027243.hdr.sgml : 20100517
<ACCEPTANCE-DATETIME>20100517143059
ACCESSION NUMBER:		0001181431-10-027243
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100513
FILED AS OF DATE:		20100517
DATE AS OF CHANGE:		20100517

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OConnor John MB
		CENTRAL INDEX KEY:			0001351416

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-01070
		FILM NUMBER:		10837657

	MAIL ADDRESS:	
		STREET 1:		C/O OLIN CORPORATION
		STREET 2:		190 CARONDELET PLAZA SUITE 1530
		CITY:			CLAYTON
		STATE:			MO
		ZIP:			63105

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OLIN CORP
		CENTRAL INDEX KEY:			0000074303
		STANDARD INDUSTRIAL CLASSIFICATION:	CHEMICALS & ALLIED PRODUCTS [2800]
		IRS NUMBER:				131872319
		STATE OF INCORPORATION:			VA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		OLIN CORP
		STREET 2:		190 CARONDELET PLAZA SUITE 1530
		CITY:			CLAYTON
		STATE:			MO
		ZIP:			63105
		BUSINESS PHONE:		3144801400

	MAIL ADDRESS:	
		STREET 1:		OLIN CORP
		STREET 2:		190 CARONDELET PLAZA SUITE 1530
		CITY:			CLAYTON
		STATE:			MO
		ZIP:			63105

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	OLIN MATHIESON CHEMICAL CORP
		DATE OF NAME CHANGE:	19691008
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd274944.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-05-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000074303</issuerCik>
        <issuerName>OLIN CORP</issuerName>
        <issuerTradingSymbol>OLN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001351416</rptOwnerCik>
            <rptOwnerName>OConnor John MB</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OLIN CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>190 CARONDELET PLAZA SUITE 1530</rptOwnerStreet2>
            <rptOwnerCity>CLAYTON</rptOwnerCity>
            <rptOwnerState>MO</rptOwnerState>
            <rptOwnerZipCode>63105</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock $1 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2010-05-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1228</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>20.37</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8853</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Family Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-05-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>3200</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3200</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30730.55</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares of common stock granted under the Amended and Restated 1997 Stock Plan for Non-employee Directors, the Company's formula director compensation plan.</footnote>
        <footnote id="F2">Phantom shares of common stock are also credited periodically to a deferred stock account under the Amended and Restated 1997 Stock Plan for Non-employee directors and are settled in common stock or cash following the date the reporting person ceases to be a director.</footnote>
        <footnote id="F3">Security converts to common stock on a one-for-one basis.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ B. M. Pantalone, Attorney-in-Fact</signatureName>
        <signatureDate>2010-05-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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