Psycho (1959) is a suspense novel by Robert Bloch.

Bloch's novel was adapted in 1960 into the feature film by director Alfred Hitchcock. It was written by Joseph Stefano and starred Anthony Perkins as Bates and Janet Leigh in an Academy Award-nominated performance as Marion Crane (changed from "Mary" for the film, as there was a Mary Crane in Phoenix at that time). Hitchcock helped devise a promotional and marketing scheme for his film that insisted that critics would not get advance screenings, and that no one would be admitted into the theater after the film began. The promotional scheme also exhorted audiences not to reveal the twist ending.

The Hitchcock version of the film is rated number 1 on the American Film Institute's list of one hundred most thrilling films.