It Happened One Night is a 1934 American pre-Code romantic comedy film with elements of screwball comedy directed and co-produced by Frank Capra, in collaboration with Harry Cohn, in which a pampered socialite (Claudette Colbert) tries to get out from under her father's thumb and falls in love with a roguish reporter (Clark Gable). The screenplay by Robert Riskin is based on the August 1933 short story "Night Bus" by Samuel Hopkins Adams, which provided the shooting title. Classified as a "pre-Code" production, the film is among the last romantic comedies created before the MPPDA began rigidly enforcing the 1930 Motion Picture Production Code in July 1934. It Happened One Night was released just four months prior to that enforcement.

It is seen as one of the greatest films ever made. It Happened One Night is the first of only three films (along with One Flew Over the Cuckoo's Nest and The Silence of the Lambs) to win all five major Academy Awards: Best Picture, Best Director, Best Actor, Best Actress, and Best Adapted Screenplay. In 1993, it was selected for preservation in the U.S. National Film Registry by the Library of Congress, being deemed "culturally, historically, or aesthetically significant". In 2013, the film underwent an extensive restoration by Sony Pictures. The film's copyright was renewed in 1962, and under current United States law it will enter the public domain on January 1, 2030.