Owen Thomas Edgar (June 17, 1831 – September 3, 1929) was, according to data from the United States Department of Veterans Affairs, the longest surviving U.S. veteran of the Mexican-American War. He was born in Philadelphia, Pennsylvania. He enlisted in the United States Navy as a 2nd-class apprentice on February 10, 1846, and was discharged August 8, 1849. Edgar saw service on the frigates Potomac, Allegheny, Pennsylvania and Experience.