Pierre Soulé (August 31, 1801 – March 26, 1870) was an attorney, politician and diplomat from Louisiana during the mid-19th century. Serving as a United States Senator from 1849 to 1853, he resigned to accept appointment as U.S. Minister to Spain, a post he held until 1855.He is likely best known for his role in writing the 1854 Ostend Manifesto, part of an attempt by Southern slaveholders to gain support for the US to annex Cuba to the United States.