The Helicopter Spies is a 1968 feature-length film version of The Man from U.N.C.L.E.'s fourth season two-part episode "The Prince of Darkness Affair". The episodes were originally broadcast in the United States on October 2, 1967, and October 9, 1967, on NBC. Like the television series, it stars Robert Vaughn and David McCallum. It is the seventh such feature film that used as its basis a reedited version of one or more episodes from the series. The film was directed by Boris Sagal and written by Dean Hargrove. Carol Lynley, Bradford Dillman, Lola Albright, John Dehner, Julie London, H.M. Wynant, and Roy Jenson also star in the film.

David Keith McCallum was a Scottish actor and musician. He gained wide recognition in the 1960s for playing secret agent Illya Kuryakin in the television series The Man from U.N.C.L.E. His other notable television roles include Simon Carter in Colditz (1972–1974) and Steel in Sapphire & Steel (1979–1982). Beginning in 2003, McCallum gained renewed international popularity for his role as NCIS medical examiner Dr. Donald "Ducky" Mallard in the American television series NCIS, which he played for 20 seasons until his death. On film, McCallum notably appeared in The Great Escape (1963), and as Judas Iscariot in The Greatest Story Ever Told (1965).