One Flew Over the Cuckoo's Nest is a 1975 American psychological drama film directed by Miloš Forman, based on the novel One Flew Over the Cuckoo's Nest by Ken Kesey. The film stars Jack Nicholson as a new patient at a mental institution, alongside Louise Fletcher as a sadistic nurse. The supporting cast is Will Sampson, Danny DeVito, Sydney Lassick, William Redfield, and the film debuts of Christopher Lloyd and Brad Dourif.

Jan Tomáš "Miloš" Forman was a Czech-American film director, screenwriter, actor, and professor who rose to fame in his native Czechoslovakia before emigrating to the United States in 1968. Throughout Forman's career he won two Academy Awards, a BAFTA Award, three Golden Globe Awards, a Golden Bear, a César Award, and the Czech Lion.