What was the title of Billy Wilder's final film as director?

Billy Wilder’s final film as director was Buddy Buddy. Released in 1981, it was a comedy starring Jack Lemmon as a suicidal television censor and Walter Matthau as a professional hitman whose lives collide in a hotel. The film was Wilder’s last feature as both director and screenwriter.

Buddy Buddy was adapted from Francis Veber’s play Le Contrat and Édouard Molinaro’s French film L’emmerdeur, released in English as A Pain in the Ass. Wilder had previously worked with Lemmon on several celebrated films, including Some Like It Hot, The Apartment, and Avanti!, while Matthau had won an Oscar under Wilder’s direction in The Fortune Cookie.

The film is sometimes confused with Fedora, Wilder’s previous movie, because Fedora was his last film of the 1970s and is often discussed as his late-career farewell. After Buddy Buddy, Wilder and longtime collaborator I. A. L. Diamond developed additional ideas, but none reached production. Wilder later expressed disappointment with the film, yet it remains the definitive endpoint of his directing career.