Marni Nixon (born February 22, 1930) is an American soprano and playback singer for featured actresses in movie musicals. She is most famous for dubbing the singing voices of the leading actresses in films, including The King and I, West Side Story, and My Fair Lady.

Nixon's varied career has included, besides her voice work in films, some film roles of her own, television, opera, concerts with major symphony orchestras around the world, musicals on stage throughout the United States and recordings.