Marilyn Cooper (December 14, 1934 – April 22, 2009) was an American actress known primarily for her work on the Broadway stage. 　　Born in New York City, Cooper made her Broadway debut in 1956 in the chorus of Mr. Wonderful. Next she was in the chorus of a revival of Brigadoon. 　　In 1957, she played Rosalia, a Sharks girl who wants to go back to Puerto Rico ("Puerto Rico, you lovely island"), in the original Broadway production of West Side Story. In 1959, she went on to create the ensemble role of Agnes, the leader of the Hollywood Blondes, in the original Broadway production Gypsy. Before leaving the show, she briefly understudied the title role of Louise and played the part for one performance without having had an opportunity to rehearse Act 2. In 1962, she graduated to a leading role, playing the ingenue in I Can Get It for You Wholesale, opposite Elliott Gould and Sheree North (the show marked Barbra Streisand's Broadway debut at age 19).