What is the only X-rated film to win the Oscar for Best Picture?

Answer 1

Midnight Cowboy (1969) is the only X-rated film ever to win the Academy Award for Best Picture. The film was originally given an R rating by the MPAA, but United Artists' studio head Arthur Krim elected to self-apply the X-rating, which at the time merely meant "Adults Only" and did not connote pornography. The X-rating was a self-applied rating. It was not a trademarked rating; therefore it became very popular in the marketing of low budget sexually explicit exploitation films, and in 1970 the studio resubmitted Midnight Cowboy to the MPAA and it received its original R-rating without edits. Midnight Cowboy has also been deemed "culturally significant" by the Library of Congress and selected for preservation in the United States National Film Registry.