Son of Gregory Peck and Greta Kukkonen.
Stephen was drafted into the U.S. Marine Corps in August 1968 after graduating from Northwestern University. He served as a lieutenant in the 1st Marine Division near Da Nang from 1969 to 1970. He left the Marines in March 1971. Gregory Peck was proud of his son's military service even though he disagreed with the war itself.
Father of Ethan Peck and stepfather of Marisa Matarazzo.
Brother of Jonathan Peck (b. 1944 - d. 1975) and Carey Paul Peck (b. 1949).