While at Notre Dame Scott joined the Marine Corps Reserve, and received a commission as a second lieutenant. He was called to active duty prior to the outbreak of the war. He served with the 3rd Marine Division and saw action during the Bougainville and Guam campaigns. He received the Silver Star, Bronze Star with valor clasp, and the Purple Heart. Scott was called to active duty during the Korean War, serving in Washington, D.C., as a public relations officer. He retired from the Marine Reserves with the rank of brigadier general in 1959.