Equus is a 1977 psychological drama film directed by Sidney Lumet and written by Peter Shaffer, based on his play of the same name. The film stars Richard Burton, Peter Firth, Colin Blakely, Joan Plowright, Eileen Atkins, and Jenny Agutter. The story concerns a psychiatrist treating a teenager who has blinded horses in a stable, attempting to find the root of his horse worship.

Sir Peter Levin Shaffer was an English playwright, screenwriter, and novelist. He wrote numerous award-winning plays, of which several were adapted into films.