Unfaithfully Yours is a 1948 American screwball black comedy film written and directed by Preston Sturges, and starring Rex Harrison, Linda Darnell, Rudy Vallée and Barbara Lawrence.

The film is about a jealous symphony conductor who imagines three different ways to deal with the supposed infidelity of his beautiful wife—murder, forbearance, and a suicidal game of Russian roulette—during a concert of three inspiring pieces of classical music.

Sweeney summarizes the report for Arthur: his wife was spied late at night wearing only a nightgown as she went to the hotel room of Alfred's secretary, Anthony Windborn, a man closer in age to her own, where she stayed for thirty-eight minutes.

Preston Sturges wrote the original screen story for Unfaithfully Yours in 1932 – the idea came to him when a melancholy song on the radio influenced him while working on writing a comic scene.

[2] Reviewing the film for The New York Times, Bosley Crowther remarked that "for all its occasional slow stretches and its fleeting delays on the punch, Unfaithfully Yours is a dilly of a sardonic slapstick comedy."

He lauded the film for having great wit, a satirical moral, strong performances by Rex Harrison and Linda Darnell, and the unique authorial touch of Preston Sturges.

[13] The Criterion Company released a DVD of the film, featuring additional audio commentary by Sturges scholars James Harvey, Diane Jacobs, and Brian Henderson.

[14] Twentieth Century-Fox remade the film in 1984 under the same title, with Dudley Moore, Nastassja Kinski, Armand Assante and Albert Brooks and directed by Howard Zieff.