Samuel Perry "Powhatan" Carter (August 6, 1819 – May 26, 1891) was a United States naval officer who served in the Union Army as a brevet major general during the American Civil War and became a rear admiral in the postbellum United States Navy. He was the first and thus far only United States officer to have been commissioned both a general officer and a Naval flag officer. C.f.: Joseph D. Stewart, Major General, (United States Marine Corps) and Vice Admiral (United States Maritime Service), the USMS being a civilian agency.