As filed with the Securities and Exchange Commission on November 3, 2010

Registration No. 333-168736

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Amendment No. 3

to

Form S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Triangle Petroleum Corporation

(Exact name of registrant as specified in its charter)

1625 Broadway, Suite 780

Denver, CO 80202

(303) 260-7125

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

Peter J. Hill

President and Chief Executive Officer

Triangle Petroleum Corporation

1625 Broadway, Suite 780

Denver, CO 80202

(303) 260-7125

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after the effective date of this registration statement.

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933 check the following box.  ¨

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment which specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933 or until the registration statement shall become effective on such date as the Commission acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This Amendment No. 3 to the Registration Statement on Form S-1 (File No. 333-168736) is filed solely to file Exhibit 3.5. Accordingly, the preliminary prospectus has been omitted.

PART II

INFORMATION NOT REQUIRED IN PROSPECTUS

The following table sets forth the costs and expenses, other than underwriting discounts and commissions, to be paid by the registrant in connection with the sale of the shares of common stock being registered hereby. All amounts are estimates except for the SEC registration fee and the FINRA filing fee.

Chapter 78 of the Nevada Revised Statutes (“NRS”) provides that a corporation may indemnify any person who was or is a party or is threatened to be made a party to any threatened, pending or completed action, suit or proceeding whether civil, criminal, administrative or investigative (other than an action by or in the right of the corporation) by reason of the fact that he is or was a director, officer, employee or agent of the corporation, or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement actually and reasonably incurred by him in connection with such action, suit or proceeding if he is not liable pursuant to NRS Section 78.138 or acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation, and, with respect to any criminal action or proceeding, had no reasonable cause to believe his conduct was unlawful. NRS Chapter 78 further provides that a corporation similarly may indemnify any such person serving in any such capacity who was or is a party or is threatened to be made a party to any threatened, pending or completed action or suit by or in the right of the corporation to procure a judgment in its favor by reason of the fact that he is or was a director, officer, employee or agent of the corporation or is or was serving at the request of the corporation as a director, officer, employee or agent of another corporation, partnership, joint venture, trust or other enterprise, against expenses (including attorneys’ fees) actually and reasonably incurred in connection with the defense or settlement of such action or suit if he is not liable pursuant to NRS Section 78.138 or acted in good faith and in a manner he reasonably believed to be in or not opposed to the best interests of the corporation and except that no indemnification shall be made in respect of any claim, issue or matter as to which such person shall have been adjudged, after exhaustion of all appeals, to be liable to the corporation unless and only to the extent that the court or other court of competent jurisdiction in which such action or suit was brought shall determine upon application that, despite the adjudication of liability but in view of all of the circumstances of the case, such person is fairly and reasonably entitled to indemnity for such expenses which the court or other court of competent jurisdiction shall deem proper.

Our bylaws provide that we may indemnify our officers, directors, employees, agents and any other persons to the maximum extent permitted by the NRS.

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On August 6, 2010, we completed a private placement with certain accredited investors, pursuant to which such investors purchased an aggregate of 2,044,187 shares of our common stock at a purchase price of $0.43 per share (without giving effect to the reverse stock split), yielding us aggregate gross proceeds of approximately $880,000 and net proceeds of approximately $836,000. Our common stock was offered and sold in reliance on the private placement exemption from registration under Section 4(2) of the Securities Act, and Regulation D promulgated thereunder, or Regulation D. We relied on this exemption based on applicable facts, including that (i) the offers and sales were made to a limited number of persons, all of whom represented that they were “accredited investors” (as such term is defined in Regulation D), (ii) no general solicitation or advertising was used in connection with the offering and sale of our common stock and (iii) the investors’ represented that they were acquiring our common stock for investment only. Johnson Rice & Company L.L.C. served as lead placement agent for the private placement.

On March 16, 2010, we completed a private placement with certain accredited investors, pursuant to which such investors purchased an aggregate of 27,993,939 shares of our common stock at a purchase price of $0.33 per share (without giving effect to the reverse stock split), yielding us aggregate gross proceeds of approximately $9,238,000 and net proceeds of approximately $8,300,000. Our common stock was offered and sold in reliance on the private placement exemption from registration under Section 4(2) of the Securities Act and Regulation D. We relied on this exemption based on applicable facts, including that (i) the offers and sales were made to a limited number of persons, all of whom represented that they were “accredited investors” (as such term is defined in Regulation D), (ii) no general solicitation or advertising was used in connection with the offering and sale of our common stock and (iii) the investors’ represented that they were acquiring our common stock for investment only. Johnson Rice & Company L.L.C. served as lead placement agent for the private placement.

On June 3, 2008, we sold an aggregate of 18,257,500 units to certain accredited investors for aggregate proceeds of $25,560,500. Each unit consisted of one share of our common stock and one-half of a warrant (without giving effect to the reverse stock split), with each whole warrant entitling the holder to purchase one share of our common stock exercisable at a price of $2.25 for a period of two years (without giving effect to the reverse stock split). The warrants expired in June 2010. The units were offered and sold in reliance on the private placement exemption from registration under Section 4(2) of the Securities Act and Regulation D. We relied on this exemption based on applicable facts, including that (i) the offers and sales were made to a limited number of persons, all of whom represented that they were “accredited investors” (as such term is defined in Regulation D), (ii) no general solicitation or advertising was used in connection with the offering and sale of the units and (iii) the investors’ represented that they were acquiring the units for investment only.

(a) Exhibits.

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EXHIBIT INDEX

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(b) Financial statement schedules.

Not applicable.

Insofar as indemnification for liabilities arising under the Securities Act may be permitted to directors, officers and controlling persons of the registrant pursuant to the foregoing provisions, or otherwise, the registrant has been advised that in the opinion of the SEC such indemnification is against public policy as expressed in the Securities Act and is, therefore, unenforceable. In the event that a claim for indemnification against such liabilities (other than the payment by the registrant of expenses incurred or paid by a director, officer or controlling person of the registrant in the successful defense of any action, suit or proceeding) is asserted by such director, officer or controlling person in connection with the securities being registered, the registrant will, unless in the opinion of its counsel the matter has been settled by controlling precedent, submit to a court of appropriate jurisdiction the question whether such indemnification by it is against public policy as expressed in the Securities Act and will be governed by the final adjudication of such issue.

The undersigned registrant hereby undertakes that:

(1) For purposes of determining any liability under the Securities Act, the information omitted from the form of prospectus filed as part of this registration statement in reliance upon Rule 430A and contained in a form of prospectus filed by the Registrant pursuant to Rule 424(b)(1) or (4) or 497(h) under the Securities Act shall be deemed to be part of this registration statement as of the time it was declared effective.

(2) For the purpose of determining any liability under the Securities Act, each post effective amendment that contains a form of prospectus shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

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Signatures

Pursuant to the requirements of the Securities Act, the registrant has duly caused this registration statement to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Denver, Colorado, on the 3^rd day of November, 2010.

Pursuant to the requirements of the Securities Act, as amended, this registration statement has been signed below by the following persons in the capacities and on the dates indicated.

Signatures

Pursuant to the requirements of the Securities Act, this registration statement has been signed by the following persons in the capacities indicated on.

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EXHIBIT INDEX

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