Four Nights of a Dreamer (French: Quatre nuits d'un rêveur) is a 1971 French romantic comedy-drama film written and directed by Robert Bresson. The film stars Isabelle Weingarten, in her feature film debut, and Guillaume des Forêts. A loose adaptation of Fyodor Dostoyevsky's short story "White Nights," the film tells the story of a down-on-his-luck artist (des Forêts) who attempts to prevent a heartbroken woman (Weingarten) from committing suicide by spending four consecutive evenings with her on the streets of Paris.

On release, Four Nights of a Dreamer was praised for its cinematography and romantic sensuality. Today, it is one of Bresson's more obscure films, in part due to complexities regarding the distribution rights. Despite (or perhaps because of) its unusually light tone for a late-style Bresson film, it has been described as one of Bresson's most underrated films. A 4K restoration was released in 2024.