F for Fake (French: Vérités et mensonges, "Truths and lies") is the last major film completed by Orson Welles, who directed, co-wrote, and starred in the film. Initially released in 1974, it focuses on Elmyr de Hory's recounting of his career as a professional art forger; de Hory's story serves as the backdrop for a fast-paced, meandering investigation of the natures of authorship and authenticity, as well as the basis of the value of art. Loosely a documentary, the film operates in several different genres and has been described as a kind of film essay.

Far from serving as a traditional documentary on Elmyr de Hory, the film also incorporates Welles's companion Oja Kodar, notorious "hoax-biographer" Clifford Irving, and Orson Welles himself, in an autobiographical role.

Several narratives are woven together throughout the film, including those of de Hory, Irving, Welles, Howard Hughes and Kodar.

About de Hory, we learn that he was a struggling artist who turned to forgery out of desperation, only to see the greater share of the profits from his deceptions go to doubly unscrupulous art dealers. As partial compensation for that injustice, he is maintained in a villa in Ibiza by one of his dealers. What is only hinted at in Welles's documentary is that de Hory had recently served a two-month sentence in a Spanish prison for homosexuality and consorting with criminals. (De Hory would commit suicide a few years after the release of Welles' film, on hearing that Spain had agreed to turn him over to the French authorities.)