North by Northwest is a 1959 American spy thriller film produced and directed by Alfred Hitchcock, starring Cary Grant, Eva Marie Saint, and James Mason. The original screenplay written by Ernest Lehman was intended to be the basis for "the Hitchcock picture to end all Hitchcock pictures".

North by Northwest is a tale of mistaken identity: an innocent man is pursued across the United States by agents of a mysterious organization that aims to prevent him from blocking their plan to smuggle microfilm containing government secrets out of the country. It is one of several Hitchcock films featuring a musical score by Bernard Herrmann and an opening title sequence by graphic designer Saul Bass. The film was the first to feature extended use of kinetic typography in its opening credits.

North by Northwest is listed among the canonical Hitchcock films of the 1950s and is often ranked among the greatest films. In 1995, the Library of Congress selected North by Northwest for preservation in the National Film Registry for being "culturally, historically, or aesthetically significant". After its first screening, reviewers for The New Yorker and The New York Times hailed it as comedic, sophisticated self-parody.