A spokesman for her agency, Act 1, said that she had died after a long illness but provided no other details.
The baby-faced Ms. Schneider was only 19 when the Italian director Bernardo Bertolucci chose her above a hundred other actresses for the role of the free-spirited, mysterious Jeanne in “Last Tango” because, he once said, she seemed “like a Lolita, but more perverse.”
In the film, Jeanne enters into a brief but torrid affair with a recently widowed American, played by Brando. Their erotically charged relationship, played out in an empty apartment near the Bir Hakeim Bridge in Paris, shocked audiences on the film’s release in 1972, especially a scene in which Brando pins Ms. Schneider to the floor and, taking out a stick of butter, seems to perform anal intercourse on her. The Motion Picture Association of America gave the film an X rating.
The role fixed Ms. Schneider in the public mind as a figurehead of the sexual revolution, and she spent years trying to move beyond the role, and the public fuss surrounding it. “I felt very sad because I was treated like a sex symbol,” she told The Daily Mail of London in 2007. “I wanted to be recognized as an actress, and the whole scandal and aftermath of the film turned me a little crazy and I had a breakdown. Now, though, I can look at the film and like my work in it.”
The famous butter scene, she said, was not in the script and made it into the film only at Brando’s insistence. “I felt humiliated and to be honest, I felt a little raped, both by Marlon and by Bertolucci,” she said. “After the scene, Marlon didn’t console me or apologize. Thankfully, there was just one take.”
Ms. Schneider later appeared opposite Jack Nicholson in “The Passenger” (1975), directed by Michaelangelo Antonioni, and she went on to work with important directors like René Clément in “The Baby-Sitter” (1975) and Jacques Rivette in “Merry-Go-Round” (1981), but her film career remained a minor one after the early 1970s, in part because of a turbulent personal life that included drug abuse, at least one suicide attempt and messy affairs with both men and women.