Exhibit 3.1

AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

OF

PHILLIPS 66

FIRST: The name of the Corporation is Phillips 66 (hereinafter the “Corporation”).

SECOND: The address of the registered office of the Corporation in the State of Delaware is 2711 Centerville Road, Suite 400, in the City of Wilmington, County of New Castle, 19808. The name of its registered agent at that address is Corporation Service Company.

THIRD: The purpose of the Corporation is to engage in any lawful act or activity for which a corporation may be organized under the General Corporation Law of the State of Delaware as set forth in Title 8 of the Delaware Code (the “DGCL”).

FOURTH: A. AUTHORIZED SHARES. The total number of shares of stock that the Corporation shall have authority to issue is 3,000,000,000 (three billion) of which (i) 2,500,000,000 (two billion, five hundred million) shares shall be shares of Common Stock, par value $.01 per share (the “Common Stock”), and (ii) 500,000,000 (five hundred million) shares shall be shares of Preferred Stock, par value $.01 per share (the “Preferred Stock”). The number of authorized shares of any of the Preferred Stock or the Common Stock may be increased or decreased (but not below the number of shares thereof then outstanding) by the affirmative vote of the holders of a majority in voting power of the stock of the Corporation entitled to vote thereon irrespective of the provisions of Section 242(b)(2) of the DGCL (or any successor provision thereto), and no vote of the holders of any of the Preferred Stock or the Common Stock voting separately as a class shall be required therefor.

B. PREFERRED STOCK. The Board of Directors is hereby expressly authorized, by resolution or resolutions, to provide, out of the unissued shares of Preferred Stock, for series of Preferred Stock and, with respect to each such series, to fix the number of shares constituting such series and the designation of such series, and the voting powers, preferences and relative, participating, optional or other special rights, if any, and any qualifications, limitations or restrictions thereof, of the shares of such series. The voting powers, preferences and relative, participating, optional and other special rights, if any, of each series of Preferred Stock, and any qualifications, limitations or restrictions thereof, if any, may differ from those of any and all other series at any time outstanding.

C. COMMON STOCK.

(1) Subject to the rights of the holders of Preferred Stock, and subject to any other provisions of this Certificate of Incorporation (“Certificate of Incorporation”), holders of Common Stock shall be entitled to receive such dividends and other distributions in cash, stock of any corporation or property of the Corporation as may be declared thereon by the Board of Directors from time to time out of assets or funds of the Corporation legally available therefor and shall share equally on a per share basis in all such dividends and other distributions.

(2) (a) At every meeting of the stockholders of the Corporation every holder of Common Stock shall be entitled to one vote in person or by proxy for each share of Common Stock standing in his or her name on the transfer books of the Corporation in connection with the election of directors and all other matters submitted to a vote of stockholders; provided, however, that, except as otherwise required by law, holders of Common Stock, as such, shall not be entitled to vote on any amendment to this Certificate of Incorporation (including any Certificate of Designation relating to any series of Preferred Stock) that relates solely to the terms of one or more outstanding series of Preferred Stock if the holders of such affected series are entitled, either separately or together with the holders of one or more other such series, to vote thereon pursuant to this Certificate of Incorporation (including any Certificate of Designation relating to any series of Preferred Stock) or pursuant to the DGCL.

(b) The affirmative vote of shares representing not less than 80% of the votes entitled to be cast by the Voting Stock shall be required to alter, amend or adopt any provision inconsistent with or repeal paragraph (C)(4)(b) of this Article FOURTH, Article FIFTH, Article SEVENTH or Article EIGHTH or any provision of this paragraph (C)(2)(b), and the affirmative vote of shares representing not less than 80% of the votes entitled to be cast by the Voting Stock, acting on the unanimous recommendation of the entire Board of Directors, shall be required to alter, amend or adopt any provision inconsistent with or repeal Article FIRST. “Voting Stock” shall mean the then outstanding shares of capital stock entitled to vote generally on the election of directors and shall exclude any class or series of capital stock only entitled to vote in the event of dividend arrearages thereon, whether or not at the time of determination there are any such dividend arrearages.

(c) Every reference in this Certificate of Incorporation to a majority or other proportion of shares, or a majority or other proportion of the votes of shares, of Voting Stock shall refer to such majority or other proportion of the votes to which such shares of Voting Stock are entitled.

(d) At any meeting of stockholders, the presence in person or by proxy of the holders of shares of capital stock entitled to cast a majority of all the votes which could be cast at such meeting by the holders of all of the outstanding shares of capital stock of the Corporation entitled to vote at such meeting shall constitute a quorum.

(3) In the event of any dissolution, liquidation or winding up of the affairs of the Corporation, whether voluntary or involuntary, after payment in full of the amounts required to be paid to the holders of Preferred Stock, the remaining assets and funds of the Corporation shall be distributed pro rata to the holders of Common Stock. For purposes of this paragraph (C)(3), the voluntary sale, conveyance, lease, exchange or transfer (for cash, shares of stock, securities or other consideration) of all or substantially all of the assets of the Corporation or a consolidation or merger of the Corporation with one or more other corporations or other entities (whether or not the Corporation is the corporation surviving such consolidation or merger) shall not be deemed to be a liquidation, dissolution or winding up, voluntary or involuntary.

(4) (a) All rights to vote and all voting power (including, without limitation thereto, the right to elect directors) shall be vested exclusively in the holders of Common Stock, except as otherwise expressly provided in this Certificate of Incorporation, in a Certificate of Designation with respect to any Preferred Stock or as otherwise expressly required by applicable law.

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(b) No stockholder shall be entitled to exercise any right of cumulative voting.

FIFTH: A. The business and affairs of the Corporation shall be managed by or under the direction of a Board of Directors. The total number of directors constituting the entire Board shall be not less than six nor more than twenty as determined from time to time by resolution adopted by affirmative vote of a majority of the entire Board of Directors. The directors, other than those who may be elected by the holders of any series of Preferred Stock under specified circumstances, shall be divided, with respect to the time for which they severally hold office, into three classes, as nearly equal in number as is reasonably possible, each with a term of office to expire at the third succeeding annual meeting of stockholders after their election, with each director to hold office until his or her successor shall have been duly elected and qualified. Unless otherwise required by law, any vacancy on the Board of Directors or newly created directorship may be filled only by a majority of the directors then in office, though less than a quorum, or by a sole remaining director, and the directors so chosen shall hold office for a term expiring at the annual meeting of stockholders at which the term of office of the class to which they have been appointed expires and until their successors are duly elected and qualified, or until their earlier death, resignation, removal or departure from the Board of Directors for other cause.

Notwithstanding the foregoing, whenever the holders of outstanding shares of one or more series of Preferred Stock are entitled to elect a director or directors of the Corporation separately as a series or together with one or more other series pursuant to a resolution of the Board of Directors providing for the establishment of such series, such director or directors shall not be subject to the foregoing provisions of this Article FIFTH, and the election, term of office, removal and filling of vacancies in respect of such director or directors shall be governed by the resolution of the Board of Directors so providing for the establishment of such series and by applicable law.

B. Subject to applicable law, any director or the entire Board of Directors may only be removed with cause, such removal to be by the affirmative vote of the shares representing at least a majority of the votes entitled to be cast by the Voting Stock.

Notwithstanding the foregoing, whenever holders of outstanding shares of one or more series of Preferred Stock are entitled to elect directors of the Corporation pursuant to the provisions applicable in the case of arrearages in the payment of dividends or other defaults contained in the resolution or resolutions of the Board of Directors providing for the establishment of any such series, any such director of the Corporation so elected may be removed in accordance with the provisions of such resolution or resolutions.

C. There shall be no limitation on the qualification of any person to be a director or on the ability of any director to vote on any matter brought before the Board or any Board committee, except (i) as required by applicable law, (ii) as set forth in this Certificate of Incorporation or (iii) any By-Law adopted by the Board of Directors with respect to the eligibility for election as a director or the qualification for continuing service as a director upon reaching a specified age or, in the case of employee directors, with respect to the qualification for continuing service of directors upon ceasing employment from the Corporation.

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D. Except as (i) required by applicable law or (ii) set forth in this Certificate of Incorporation, at all meetings of the Board of Directors, a majority of the entire Board of Directors shall constitute a quorum for the transaction of business and the act of a majority of the directors present at any meeting at which there is a quorum shall be the act of the Board of Directors.

E. The following provisions are inserted for further definition, limitation and regulation of the powers of the Corporation and of its directors and stockholders:

(1) The By-Laws of the Corporation may be adopted, altered, amended or repealed (i) by the affirmative vote of the shares representing a majority of the votes entitled to be cast by the Voting Stock; PROVIDED, HOWEVER, that any proposed alteration, amendment or repeal of, or the adoption of any By-Law inconsistent with, Section 3, 7, 10, 11, 12 or 13 of Article II of the By-Laws or Section 1, 2 or 11 of Article III of the By-Laws or Section 4, 5 or 12 of Article IV of the By-Laws (in each case, as in effect on the date hereof), or the alteration, amendment or the repeal of, or the adoption of any provision inconsistent with this sentence, by the stockholders shall require the affirmative vote of shares representing not less than 80% of the votes entitled to be cast by the Voting Stock; and PROVIDED, FURTHER, HOWEVER, that in the case of any such stockholder action at a special meeting of stockholders, notice of the proposed alteration, amendment, repeal or adoption of the new By-Law or By-Laws must be contained in the notice of such special meeting, or (ii) by action of the Board of Directors of the Corporation; provided, however, that the case of any such action at a meeting of the Board of Directors, notice of the proposed alteration, amendment, repeal or adoption of the new By-Law or By-Laws must be given not less than two days prior to the meeting. The Provisions of this paragraph (E)(1) of this Article FIFTH are subject to Section 12 of Article IV of the By-Laws.

(2) In addition to the powers and authority hereinbefore or by statute expressly conferred upon them, the directors are hereby empowered to exercise all such powers and do all such acts and things as may be exercised or done by the Corporation, subject, nevertheless, to the provisions of the DGCL, this Certificate of Incorporation, and any By-Laws adopted by the stockholders; PROVIDED, HOWEVER, that no By-Laws hereafter adopted by the stockholders shall invalidate any prior act of the directors which would have been valid if such By-Laws had not been adopted.

SIXTH: Meetings of stockholders may be held within or without the State of Delaware, as the By-Laws may provide. The books of the Corporation may be kept (subject to any provision contained in the DGCL) outside the State of Delaware at such place or places as may be designated from time to time by the Board of Directors or in the By-Laws of the Corporation.

SEVENTH: Any action required or permitted to be taken by the stockholders of the Corporation may be effected only at a duly called annual or special meeting of such holders and may not be effected by a consent in writing by such holders in lieu of such a meeting. Except as otherwise required by law, special meetings of stockholders of the Corporation for any

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purpose or purposes may be called only by the Board of Directors pursuant to a resolution stating the purpose or purposes thereof or by the Chairman of the Board of Directors of the Corporation and any power of stockholders to call a special meeting is specifically denied. No business other than that stated in the notice of such meeting shall be transacted at any special meeting.

EIGHTH: To the fullest extent that the DGCL or any other law of the State of Delaware as it exists or as it may hereafter be amended permits the limitation or elimination of the liability of directors, no director of the Corporation shall be liable to the Corporation or its stockholders for monetary damages for breach of fiduciary duty as a director. No amendment to or repeal of this Article EIGHTH shall apply to or have any effect on the liability or alleged liability of any director of the Corporation for or with respect to any acts or omissions of such director occurring prior to such amendment or repeal.

NINTH: The Court of Chancery of the State of Delaware shall be the sole and exclusive forum for (i) any derivative action or proceeding brought on behalf of the Corporation, (ii) any action asserting a claim of breach of a fiduciary duty owed by any director or officer of the Corporation to the Corporation or the Corporation’s stockholders, creditors or other constituents, (iii) any action asserting a claim against the Corporation or any director or officer of the Corporation arising pursuant to any provision of the Delaware General Corporation Law or the Corporation’s Certificate of Incorporation or By-Laws (as either may be amended from time to time), or (iv) any action asserting a claim against the Corporation or any director or officer of the Corporation governed by the internal affairs doctrine; provided, that, if and only if the Court of Chancery of the State of Delaware dismisses any such action for lack of subject matter jurisdiction, such action may be brought in another court sitting in the State of Delaware.

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