Musical theatre is a form of theatre combining music, songs, spoken dialogue and dance. The emotional content of the piece – humor, pathos, love, anger – as well as the story itself, is communicated through the words, music, movement and technical aspects of the entertainment as an integrated whole. Since the early 20th century, musical theatre stage works have generally been called simply, "musicals".

Musicals are performed all around the world. They may be presented in large venues, such as big budget West End and Broadway theatre productions in London and New York City, or in smaller Fringe Theatre, Off-Broadway or regional productions, on tour, or by amateur groups in schools, theatres and other performance spaces. In addition to Britain and North America, there are vibrant musical theatre scenes in many countries in Europe, Latin America and Asia.

Some famous musicals include Show Boat, Oklahoma!, West Side Story, The Fantasticks, Hair, A Chorus Line, Les Misérables, The Phantom of the Opera, Rent, and The Producers.