Gidding was born in New York City and attended school at Phillips Exeter Academy; as a young man he was friends with Norman Mailer.
After graduating from Harvard University, he entered the Army Air Forces during World War II as the navigator on a B-26.
His plane was shot down over Italy, but he survived; he spent 18 months as a POW but effected an escape.
In Hollywood, Gidding entered work in television, writing for such series as Suspense and Sergeant Preston of the Yukon, and eventually moved into feature films like The Helen Morgan Story (1957), Odds Against Tomorrow (1959), The Haunting (1963), Lost Command (1966), The Andromeda Strain (1971), and The Hindenburg (1975).
Gidding taught at USC until his death from congestive heart failure at a Santa Monica hospital in 2004.