"I'll Be Back" is a song written by John Lennon, with some collaboration from Paul McCartney. It was recorded by the English rock band the Beatles for the soundtrack album to their film A Hard Day's Night (1964) but not used in the film. This song was not released in North America until Beatles '65 five months later.

A Hard Day's Night is the third studio album by the English rock band the Beatles, released on 10 July 1964 by Parlophone, with side one containing songs from the soundtrack to their film of the same name. The American version of the album was released two weeks earlier, on 26 June 1964 by United Artists Records, with a different track listing that included selections from George Martin's film score. In contrast to the Beatles' first two albums, all 13 tracks on A Hard Day's Night were written by John Lennon and Paul McCartney, showcasing the development of their songwriting partnership.