Andrew Dean Stapp (March 25, 1944 – September 3, 2014) was an American activist known for forming the American Servicemen's Union, an unofficial union for the U.S. military, in opposition to the Vietnam War. Stapp began as a student activist until he was drafted into the U.S. Army in 1966. There he rallied anti-war sentiment, leading to two highly publicized courts-martial. After establishing the American Servicemen's Union, Stapp was discharged for subversive activity. He was married to Deirdre Griswold; both were members of the Workers World Party.