Miracle on 34th Street (initially released as The Big Heart in the United Kingdom) is a 1947 American Christmas comedy-drama film released by 20th Century-Fox, written and directed by George Seaton and based on a story by Valentine Davies. It stars Maureen O'Hara, John Payne, Natalie Wood, and Edmund Gwenn. The story takes place between Thanksgiving and Christmas in New York City, and focuses on the effect of a department store Santa Claus who claims to be the real Santa. The film has become a perennial Christmas favorite.

Miracle on 34th Street won three Academy Awards: Gwenn for Best Actor in a Supporting Role, Valentine Davies for Best Writing, Original Story, and George Seaton for Best Writing, Screenplay. The film was nominated for Best Picture, losing to Gentleman's Agreement. In 2005, the film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically or aesthetically significant". The Academy Film Archive preserved Miracle on 34th Street in 2009.

Davies also wrote a short novelization of the tale, which was published by Harcourt Brace simultaneously with the film's release.