A Hard Day's Night is a 1964 musical comedy film starring the English rock band the Beatles – John Lennon, Paul McCartney, George Harrison and Ringo Starr – that was released during the height of Beatlemania. Directed by Richard Lester, it was written by Alun Owen and originally released by United Artists. The musical soundtrack makes up the band's album of the same name. The film portrays 36 hours in the lives of the group as they prepare for a television performance.

The film was a commercial and critical success and was nominated for two Academy Awards, including Best Original Screenplay. Forty years after its release, Time magazine rated it as one of the 100 all-time greatest films. British critic Leslie Halliwell described it as a "comic fantasia with music; an enormous commercial success with the director trying every cinematic gag in the book" and awarded it a full four stars. The film is credited as being one of the most influential of all musical films, inspiring the Monkees' television show and pop music videos, and various other low-budget musical film vehicles starring British pop groups, such as the Gerry and the Pacemakers film Ferry Cross the Mersey (1965).

In 1999, the British Film Institute ranked it the 88th-greatest British film of the 20th century.