Inferno is a 1980 Italian supernatural horror film written and directed by Dario Argento, and starring Irene Miracle, Leigh McCloskey, Eleonora Giorgi, Daria Nicolodi and Alida Valli. The plot follows a young man's investigation into the disappearance of his sister, who had been living in a New York City apartment building that also served as a home for a powerful, centuries-old witch. The cinematography was by Romano Albani, and Keith Emerson composed the film's musical score.

A thematic sequel to Suspiria (1977), the film is the second installment of Argento's Three Mothers trilogy, though it is the first in the trilogy to explore the idea of the Three Mothers. The long-delayed concluding entry, The Mother of Tears, was released in 2007. All three films are partially derived from Thomas de Quincey's 1845 work Suspiria de Profundis, a collection of prose poetry in which he proposes the concept of three "Ladies of Sorrow" (Mater Lachrymarum, Mater Suspiriorum and Mater Tenebrarum), concurrent with the three Fates and Graces in Greek mythology.

Unlike Suspiria, Inferno received a very limited theatrical release, thus unable to match the box office success of its predecessor. While initial critical response was mostly negative, its reputation has improved considerably over the years. Kim Newman has called it "perhaps the most underrated horror movie of the 1980s." In 2005, the magazine Total Film named Inferno one of the 50 greatest horror films of all time.