Exhibit 8.1

				King & Spalding LLP 1180 Peachtree Street N.E. Atlanta, Georgia 30309-3521 Phone: 404/ 572-4600 Fax: 404/572-5100 www.kslaw.com

March 6, 2014

Piedmont Office Realty Trust, Inc.

Piedmont Operating Partnership, LP

11695 Johns Creek Parkway

Suite 350

Johns Creek, Georgia 30097

Ladies and Gentlemen:

We have acted as counsel for Piedmont Office Realty Trust, Inc., a Maryland corporation (the “Company”), and Piedmont Operating Partnership, LP, a Delaware limited partnership (the “Operating Partnership”), in connection with the registration under the Securities Act of 1933, as amended (the “1933 Act”), and the rules and regulations of the Securities and Exchange Commission (the “Commission”) thereunder, of $400,000,000 aggregate principal amount of 4.450% Senior Notes due 2024 (the “Securities”) to be sold by the Operating Partnership. This opinion is being rendered at the request of the Company and the Operating Partnership and relates to certain U.S. federal income tax matters.

FACTS AND ASSUMPTIONS RELIED UPON

In rendering the opinion expressed herein, we have examined such documents as we have deemed appropriate, including (but not limited to) (1) the analyses of qualifying income and assets prepared by the Company, (2) stock ownership information provided by the Company, (3) copies of the Registration Statement on Form S-3 dated June 4, 2013 (the “Registration Statement”), filed by the Company and the Operating Partnership with the Commission under the 1933 Act, including the prospectus contained therein, and (4) the prospectus supplement dated February 25, 2014 (the “Prospectus Supplement”) relating to the Securities. The opinions set forth in this letter also are premised on certain additional information and representations through consultation with officers of the Company, including those contained in the Officer’s Certificate delivered to us on or about the date hereof (the “Officer’s Certificate”) regarding certain facts and other matters (including among other things, representations as to the Company’s stock ownership, assets, acquisitions, revenues, and distributions) as are germane to the determination that the Company has been and will be owned and operated in such a manner that the Company has and will continue to satisfy the requirements for qualification as a REIT under the Internal Revenue Code of 1986, as amended (the “Code”). In our examination of documents, we have assumed, with your consent, that all documents submitted to us are authentic originals, or if submitted as photocopies or facsimile copies, that they faithfully reproduce the originals thereof, that all such documents have been or will be duly executed to the

Piedmont Office Realty Trust, Inc.

Piedmont Operating Partnership, LP

March 6, 2014

Page 2

extent required, that all representations and statements set forth in such documents are true and correct, and that all obligations imposed by any such documents on the parties thereto have been or will be performed or satisfied in accordance with their terms.

OPINION

Based on the foregoing, and subject to the assumptions, qualifications and limitations set forth herein, we are of the opinion that:

The opinion expressed herein is based upon the current provisions of the Code, the U.S. Treasury regulations promulgated thereunder, current administrative positions of the U.S. Internal Revenue Service, and existing judicial decisions, any of which could be changed at any time, possibly on a retroactive basis. Any such changes could adversely affect the opinion rendered herein and the tax consequences to the Company, the Operating Partnership, and the investors in the Securities. In addition, as noted above, our opinion is based solely on the documents that we have examined, the additional information that we have obtained through consultation with officers of the Company and the Operating Partnership, and the representations that have been made to us, and cannot be relied upon if any of the facts contained in such documents or in such additional information is, or later becomes, inaccurate or if any of the representations made to us is, or later becomes, inaccurate. We are not aware, however, of any facts or circumstances contrary to or inconsistent with the information, assumptions, and representations upon which we have relied for purposes of this opinion. Finally, our opinion is limited to the tax matters specifically covered thereby, and we have not been asked to address, nor have we addressed, any other tax consequences of an investment in the Securities.

Piedmont Office Realty Trust, Inc.

Piedmont Operating Partnership, LP

March 6, 2014

Page 3

This opinion is given as of the date hereof, and we assume no obligation to advise you after the date hereof of facts or circumstances that come to our attention or changes in law that occur which could affect this opinion.

We hereby consent to the filing of this opinion as an Exhibit to a Current Report on Form 8-K and to the references to our firm in the Prospectus Supplement.