The Nutcracker (Russian: Щелкунчик, tr. Shchelkunchik, IPA: [ɕːɪlˈkunʲtɕɪk] (listen)) is an 1892 two-act "fairy ballet" (Russian: балет-феерия, tr. balet-feyeriya) set on Christmas Eve at the foot of a Christmas tree in a child's imagination. The music is by Pyotr Ilyich Tchaikovsky, his Opus 71. The plot is an adaptation of E. T. A. Hoffmann's 1816 short story The Nutcracker and the Mouse King. The ballet's first choreographer was Marius Petipa, with whom Tchaikovsky had worked three years earlier on The Sleeping Beauty, assisted by Lev Ivanov. Although the complete and staged The Nutcracker ballet was not as successful as had been the 20-minute Nutcracker Suite that Tchaikovsky had premiered nine months earlier, The Nutcracker soon became popular.

Since the late 1960s, it has been danced by countless ballet companies, especially in North America. Major American ballet companies generate around 40% of their annual ticket revenues from performances of The Nutcracker. The ballet's score has been used in several film adaptations of Hoffmann's story.

Tchaikovsky's score has become one of his most famous compositions. Among other things, the score is noted for its use of the celesta, an instrument the composer had already employed in his much lesser known symphonic ballad The Voyevoda (1891).