De Sade (German: Das Ausschweifende Leben des Marquis De Sade) is a 1969 American-German drama film directed by Cy Endfield and starring Keir Dullea, Senta Berger and Lilli Palmer. It is based on the life of Donatien Alphonse François, Marquis de Sade, named Louis Alphonse Donatien in the film.

Dullea, in his first film role since the 1968 release of 2001: A Space Odyssey, plays the title character in a film characterized by its psychedelic imagery and go-go sensibilities. As the dying Marquis recalls his life out of sequence, he is terrorized by his uncle and haunted by his own past of debauchery.

It was shot at the Spandau Studios in Berlin and the Bavaria Studios in Munich. The film's sets were designed by the art director Hans Jürgen Kiebach.