Magellan Midstream Partners (MMP) 8-K Entry into a Material Definitive Agreement

Exhibit 5.1

	717 Texas Avenue, 16th floor
	Houston, TX 77002
	Tel: +1.713.546.5400  Fax: +1.713.546.5401
	www.lw.com
	FIRM / AFFILIATE OFFICES
	Abu Dhabi	Moscow
	Barcelona	Munich
	Beijing	New Jersey
	Brussels	New York
	Chicago	Orange County
July 16, 2010	Doha	Paris
	Dubai	Riyadh
	Frankfurt	Rome
	Hamburg	San Diego
	Hong Kong	San Francisco
	Houston	Shanghai
	London	Silicon Valley
Magellan Midstream Partners, L.P.	Los Angeles	Singapore
One Williams Center	Madrid	Tokyo
P.O. Box 22186	Milan	Washington, D.C.
Tulsa, Oklahoma 74121-2186

Re: Registration Statement No. 333-162929; Issuance of up to 5,750,000 common

units representing limited partner interests

Ladies and Gentlemen:

We have acted as counsel to Magellan Midstream Partners, L.P., a Delaware limited partnership (the “Partnership”), in connection with the proposed issuance of up 5,750,000 common units representing limited partner interests in the Partnership (the “Common Units”). The Common Units are included in a registration statement on Form S-3 under the Securities Act of 1933, as amended (the “Act”), filed with the Securities and Exchange Commission (the “Commission”) on November 5, 2009 (Registration No. 333-162929) (as supplemented, the “Registration Statement”). 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 the related Prospectus, other than as expressly stated herein with respect to the issue 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 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 laws of the United States of America, the Constitution of the State of Delaware and the Delaware Revised Uniform Limited Partnership Act (the “Delaware Act”), as interpreted by the federal courts and the courts of the State of Delaware, and we express no opinion with respect to any other laws.

Subject to the foregoing and the other matters set forth herein, it is our opinion that:

1. The Partnership has been duly formed and is validly existing as a limited partnership under the Delaware Act.

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2. The Common Units, when issued and delivered on behalf of the Partnership against payment therefore as described in the Registration Statement, will be duly authorized, validly issued, fully paid and non-assessable.

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 an exhibit to the Company’s Form 8-K dated July 16, 2010 and to the reference to our firm in the 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/ Latham & Watkins LLP