Operation Crossbow (later re-released as The Great Spy Mission) is a 1965 British espionage thriller set during the Second World War. This movie concerns an actual series of events where British undercover operatives targeted the German manufacturing facilities for experimental rocket-bombs.

The film was directed by Michael Anderson and stars Sophia Loren, George Peppard, Trevor Howard, John Mills, Richard Johnson, and Tom Courtenay. The screenplay was written by Emeric Pressburger (under the pseudonym "Richard Imrie"), in collaboration with Derry Quinn and Ray Rigby, from a story by Duilio Coletti and Vittoriano Petrilli. It was filmed in Panavision and Metrocolor at MGM-British Studios.

Although it is largely fictional, the movie does touch on the main aspects of the operation, which was geared to thwart the German long-range weapons programme in the final years of World War II. The story alternates between Nazi Germany's development of the V-1 flying bomb and V-2 rocket, and the efforts of British Intelligence and its agents to counter those threats. All characters speak in the appropriate language, with English subtitles for those speaking German or Dutch.