La supertestimone is a 1971 black comedy Italian film, directed by Franco Giraldi. For this film Monica Vitti was awarded with a Globo d'oro for Best Actress.

In the film, a pimp is suspected of murdering his lover. He is convicted based on the testimony of a single witness. The woman doubts her memory of the event, and manages to have his prison sentence reduced. She falls in love and marries the pimp. He prostitutes his new wife, and eventually explains to her that he was actually guilty in the murder case.