Donald Bengtsson Hamilton (March 24, 1916 ? November 20, 2006) was a U.S. writer of novels, short stories, and non-fiction about the outdoors. His novels consist mostly of paperback originals, principally spy fiction but also crime fiction and Westerns such as The Big Country. He is best known for his long-running Matt Helm series (1960-1993), which chronicles the adventures of an undercover counter-agent/assassin working for a secret American government agency. The noted critic Anthony Boucher wrote: "Donald Hamilton has brought to the spy novel the authentic hard realism of Dashiell Hammett; and his stories are as compelling, and probably as close to the sordid truth of espionage, as any now being told."

The 1958 novel, The Big Country was expanded from Hamilton's original short story Ambush at Blanco Canyon which appeared in The Saturday Evening Post (Feb 1957).

The film, The Big Country, starred Gregory Peck, Jean Simmons, Carroll Baker, Charlton Heston, Charles Bickford, Burl Ives and Chuck Connors.