Exhibit 5.1

June 6, 2016 Tesoro Logistics LP 19100 Ridgewood Parkway San Antonio, Texas 78259		Norton Rose Fulbright US LLP 2200 Ross Avenue, Suite 3600 Dallas, Texas 75201-2784 United States Tel +1 214 855 8000 Fax +1 214 855 8200 nortonrosefulbright.com

Re: Registration Statement on Form S-3

Ladies and Gentlemen:

We have acted as special counsel to Tesoro Logistics LP, a Delaware limited partnership (the “Partnership”), in connection with the filing on the date hereof with the Securities and Exchange Commission (the “Commission”) of a registration statement on Form S-3 (the “Registration Statement”) under the Securities Act of 1933, as amended (the “Act”), pertaining to the registration of common units representing limited partner interest in the Partnership (the “Common Units”).

You have provided us with a draft of the Registration Statement in the form in which it will be filed, which includes a base prospectus (the “Prospectus”). The Prospectus provides that it will be supplemented in the future by one or more supplements to the Prospectus (each a “Prospectus Supplement”). The Prospectus as supplemented by various Prospectus Supplements will provide for the sale by the Partnership of Common Units.

This opinion is being furnished in connection with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or related prospectus, other than as expressly stated herein with respect to the issuance of the Common Units.

As such counsel, we have examined such matters of fact and questions of law as we have considered appropriate for purposes of this letter. With your consent, we have relied upon certificates and other assurances of officers of Tesoro Logistics GP, LLC, the general partner of the Partnership, and others as to factual matters without having independently verified such factual matters. We are opining herein as to the Delaware Revised Uniform Limited Partnership Act, and we express no opinion with respect to the applicability thereto, or the effect thereon, of the laws of any other jurisdiction or, in the case of Delaware, any other laws, or as to any matters of municipal law or the laws of any local agencies within any state.

Subject to the foregoing and the other matters set forth herein, it is our opinion that, as of the date hereof, when an issuance of Common Units has been duly authorized by all necessary limited partnership action of the Partnership, upon issuance, delivery and payment therefor in the manner contemplated by the Registration Statement or the related prospectus or prospectus supplement and by such limited partnership action, such Common Units will be validly issued and, under the Delaware Revised Uniform Limited Partnership Act, purchasers of the Common Units will have no obligation to make further payments for their purchase of Common Units or contributions to the Partnership solely by reason of their ownership of Common Units or their status as limited partners of the Partnership, and no personal liability for the debts, obligations and liabilities of the Partnership, whether arising in contract, tort or otherwise, solely by reason of being limited partners of the Partnership.

Norton Rose Fulbright US LLP is a limited liability partnership registered under the laws of Texas.

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Tesoro Logistics LP
June 6, 2016
Page 2

This opinion is for your benefit in connection with the Registration Statement and may be relied upon by you and by persons entitled to rely upon it pursuant to the applicable provisions of the Act. We consent to your filing this opinion as Exhibit 5.1 to the Registration Statement and to the reference to our firm contained in the base prospectus under the heading “Legal Matters.” In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission thereunder.

Very truly yours,

/s/ Norton Rose Fulbright US LLP

Norton Rose Fulbright US LLP