<SEC-DOCUMENT>0001044321-11-000132.txt : 20110614
<SEC-HEADER>0001044321-11-000132.hdr.sgml : 20110614
<ACCEPTANCE-DATETIME>20110614150658
ACCESSION NUMBER:		0001044321-11-000132
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20110610
FILED AS OF DATE:		20110614
DATE AS OF CHANGE:		20110614

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LIGHTBRIDGE Corp
		CENTRAL INDEX KEY:			0001084554
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-MANAGEMENT CONSULTING SERVICES [8742]
		IRS NUMBER:				911975651
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1600 TYSONS BOULEVARD
		STREET 2:		SUITE 550
		CITY:			MCLEAN,
		STATE:			VA
		ZIP:			22102
		BUSINESS PHONE:		703.918.4904

	MAIL ADDRESS:	
		STREET 1:		1600 TYSONS BOULEVARD
		STREET 2:		SUITE 550
		CITY:			MCLEAN,
		STATE:			VA
		ZIP:			22102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Thorium Power, Ltd
		DATE OF NAME CHANGE:	20061011

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NOVASTAR RESOURCES LTD.
		DATE OF NAME CHANGE:	20051011

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NOVASTAR RESOURCES LTD
		DATE OF NAME CHANGE:	20050829

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MARXE AUSTIN W & GREENHOUSE DAVID M
		CENTRAL INDEX KEY:			0001044321

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34487
		FILM NUMBER:		11910512

	BUSINESS ADDRESS:	
		STREET 1:		C/O SPECIAL SITUATIONS FUNDS
		STREET 2:		527 MADISON AVENUE, SUITE 2600
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		2122076500

	MAIL ADDRESS:	
		STREET 1:		C/O SPECIAL SITUATIONS FUNDS
		STREET 2:		527 MADISON AVENUE, SUITE 2600
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2011-06-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001084554</issuerCik>
        <issuerName>LIGHTBRIDGE Corp</issuerName>
        <issuerTradingSymbol>LTBR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001044321</rptOwnerCik>
            <rptOwnerName>MARXE AUSTIN W &amp; GREENHOUSE DAVID M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O SPECIAL SITUATIONS FUNDS</rptOwnerStreet1>
            <rptOwnerStreet2>527 MADISON AVENUE, SUITE 2600</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.7206</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1258192</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnerships</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2011-06-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7540</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.7474</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1265732</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                    <footnoteId id="F2"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Limited Partnerships</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This is a weighted average price.</footnote>
        <footnote id="F2">This is a joint filing by Austin W. Marxe (Marxe) and David M. Greenhouse (Greenhouse).  They share voting and investment control over all securities owned by Special Situations Fund III QP, L.P. (QP), Special Situations Cayman Fund, L.P. (Cayman) and Special Situations Private Equity Fund, L.P. (PE).  791,081 shares of Common Stock are held by QP, 263,693 shares of Common Stock are held by Cayman, 210,958 shares of Common Stock are held by PE. The interest of Marxe and Greenhouse in the shares of Common Stock owned by QP, Cayman and PE is limited to the extent of his pecuniary interest.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Austin W. Marxe</signatureName>
        <signatureDate>2011-06-14</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>David M. Greenhouse</signatureName>
        <signatureDate>2011-06-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
