音乐剧（英语：Musical theater，简称Musicals），早期译称为歌舞剧，是音乐、歌曲、舞蹈、戏剧、杂耍、特技和综艺结合的一种音乐表演。它以幽默、讽刺、感伤、爱情、愤怒等情感引发剧情，再通过演员的语言、音乐、动作以及固定的演绎传达给观众。虽然音乐剧和歌剧、舞剧、话剧等舞台表演形式有相似之处，但它的独特之处在于：它对歌曲、对白、肢体动作、表演等等因素给予同样的重视。一些著名的音乐剧包括：奥克拉荷马、真善美、西城故事、悲惨世界、猫以及歌剧魅影等。

音乐剧在全世界各地都有上演，但演出最频密的地方是美国纽约市的百老汇和英国的伦敦西区。因此百老汇音乐剧这个称谓可以指在百老汇地区上演的音乐剧，又往往可是泛指所有近似百老汇风格的音乐剧。而习惯上称呼为音乐剧的戏剧，多是指西方音乐剧。

Musical theatre is a form of theatrical performance that combines songs, spoken dialogue, acting, and dance. The story and emotional content of a musical – humor, pathos, love, anger – are communicated through the words, music, movement and technical aspects of the entertainment as an integrated whole. Although musical theatre overlaps with other theatrical forms like opera and dance, it may be distinguished by the equal importance given to the music as compared with the dialogue, movement and other elements. Since the early 20th century, musical theatre stage works have generally been called, simply, musicals.