Dementia is a 1955 American black-and-white experimental horror film produced, written, and directed by John Parker, and starring Adrienne Barrett and Bruno Ve Sota. The film, which contains no dialogue, follows a young woman's nightmarish experiences during a single night in Los Angeles's skid row. Stylistically, it incorporates elements of horror, film noir, and expressionist film.

Dementia was conceived as a short film by writer-director Parker and was based on a dream relayed to him by his secretary, Barrett. He cast Barrett in the film, along with Ve Sota, and ultimately decided to expand it into a longer feature. The film received a troubled release, being banned in 1953 by the New York State Film Board before finally being released in December 1955. It was later acquired by Jack H. Harris, who edited it and incorporated voice over narration by radio personality Ed McMahon (later to be known for co-hosting The Tonight Show with Johnny Carson) before re-releasing it in 1957 under the alternate title Daughter of Horror.