Blood Simple is a 1984 American independent neo-noir crime film written, edited, produced, and directed by Joel and Ethan Coen, and starring John Getz, Frances McDormand, Dan Hedaya, and M. Emmet Walsh. Its plot follows a Texas bartender who finds himself in the midst of a murder plot when his boss discovers that he is having a love affair with his wife and he hires a private investigator to kill the couple but the investigator has his own agenda. It was the directorial debut of the Coens and the first major film of cinematographer Barry Sonnenfeld, who later became a director, as well as the feature-film debut of McDormand.

The film's title derives from the Dashiell Hammett novel Red Harvest (1929), in which the term "blood simple" describes the addled, fearful mind-set of people after prolonged immersion in violent situations. Stylistically, the film has been noted for its blending elements of neo-noir, pulp crime stories, and low-budget horror films. In 2001, a director's cut was released, the same year that it was ranked number 98 on AFI's 100 Years...100 Thrills.