Ralph Alvin Heywood (September 11, 1921 – April 10, 2007) was an American football player. He was the only National Football League player to serve in World War II, the Korean War, and the Vietnam War, serving as a Marine Corps officer for 32 years. Born in Los Angeles, California, he was an All-American for USC in 1943. Heywood died at age 85 in Bandera, Texas.