The Great Ecstasy of Robert Carmichael is a 2005 British crime film directed by Thomas Clay in his feature-length directorial debut and written by Clay and Joseph Lang. It stars Daniel Spencer as the titular character, a teenager whose life spirals out of control after experimenting with drugs with schoolmates.

The film premiered at the Cannes Film Festival as part of the Critic's Week sidebar, where it was nominated for the Camera d'Or award. It also screened at the Edinburgh Film Festival. At both premieres, the film was greeted with negative responses for its graphic violence. At Cannes, the film's ending prompted audience walkouts.