The Nutcracker and the Four Realms is a 2018 American Christmas fantasy film directed by Lasse Hallström and Joe Johnston. It is a retelling of both the 1816 short story "The Nutcracker and the Mouse King" and the 1892 ballet The Nutcracker, about a young girl who is gifted a locked egg from her deceased mother and sets out in a magical land to retrieve the key. The film stars Keira Knightley, Mackenzie Foy, Eugenio Derbez, Matthew Macfadyen, Richard E. Grant, Misty Copeland, Helen Mirren, and Morgan Freeman.

The film was announced in March 2016 with Hallström directing from a script by Powell. Much of the cast signed on that summer, and filming began in October at Pinewood Studios, lasting through January 2017. In December 2017, it was announced Johnston would direct a month of reshoots, with Hallström agreeing to Johnston receiving co-directing credit. The reshoots were written by Tom McCarthy, who went uncredited, and Powell received a sole credit as screenwriter. Composer James Newton Howard scored the film, adapting elements from Tchaikovsky's music for the 1892 ballet, while Gustavo Dudamel served as conductor, leading the London Philharmonia Orchestra.

The Nutcracker and the Four Realms premiered at the Dolby Theatre in Los Angeles on October 29, 2018, and was released by Walt Disney Studios Motion Pictures in the United States on November 2. The film was a box office disappointment, grossing $174 million worldwide against a production budget between $120–133 million and losing Disney over $65 million. It received generally negative reviews, with criticisms of its story and Knightley's performance, although the film's visual effects and aesthetics were praised.