Rosemary's Baby is a 1968 American psychological horror film written and directed by Roman Polanski, based on Ira Levin's 1967 novel of the same name. The film stars Mia Farrow as a young wife living in Manhattan who becomes pregnant, but soon begins to suspect that her elderly neighbors are members of a Satanic cult who are grooming her in order to use her baby for their rituals. The film's supporting cast includes John Cassavetes, Ruth Gordon, Sidney Blackmer, Maurice Evans, Ralph Bellamy, Patsy Kelly, Angela Dorian, and Charles Grodin in his feature film debut.

The film deals with themes related to paranoia, women's liberation, Christianity (Catholicism), and the occult. While it is primarily set in New York City, the majority of principal photography for Rosemary's Baby took place in Los Angeles throughout late 1967. The film was released on June 12, 1968, by Paramount Pictures. It was a critical and box office success, grossing over $30 million in the United States, and received near-universal acclaim from critics. The film was nominated for several accolades, including multiple Golden Globe Award nominations and two Academy Award nominations, winning Best Supporting Actress (for Ruth Gordon) and the Golden Globe in the same category. Since its release, Rosemary's Baby has been widely regarded as one of the greatest horror films of all time. In 2014, the film was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant."