Psycho is a 1959 novel by American writer Robert Bloch. The novel tells the story of Norman Bates, a caretaker at an isolated motel who struggles under his domineering mother and becomes embroiled in a series of murders. The novel is considered Bloch's most enduring work and one of the most influential horror novels of the 20th century.

Robert Albert Bloch was an American fiction writer, primarily of crime, psychological horror and fantasy, much of which has been dramatized for radio, cinema and television. He also wrote a relatively small amount of science fiction. His writing career lasted 60 years, including more than 30 years in television and film. He began his professional writing career immediately after graduation from high school, aged 17. Best known as the writer of Psycho (1959), the basis for the film of the same name by Alfred Hitchcock, Bloch wrote hundreds of short stories and over 30 novels. He was a protégé of H. P. Lovecraft, who was the first to seriously encourage his talent. However, while he started emulating Lovecraft and his brand of cosmic horror, he later specialized in crime and horror stories working with a more psychological approach.