Sunset Boulevard is a 1950 American dark comedy film noir directed by Billy Wilder and co-written by Wilder, Charles Brackett and D. M. Marshman Jr. It is named after a major street that runs through Hollywood.

The film stars William Holden as Joe Gillis, a struggling screenwriter, and Gloria Swanson as Norma Desmond, a former silent-film star who draws him into her deranged fantasy world, where she dreams of making a triumphant return to the screen. Erich von Stroheim plays Max von Mayerling, her devoted butler, and Nancy Olson, Jack Webb, Lloyd Gough, and Fred Clark appear in supporting roles. Director Cecil B. DeMille and gossip columnist Hedda Hopper play themselves, and the film includes cameo appearances by silent-film stars Buster Keaton, H. B. Warner, and Anna Q. Nilsson.

Praised by many critics when first released, Sunset Boulevard was nominated for 11 Academy Awards (including nominations in all four acting categories) and won three. It is often ranked among the greatest movies ever made. As it was deemed "culturally, historically, or aesthetically significant" by the U.S. Library of Congress in 1989, Sunset Boulevard was included in the first group of films selected for preservation in the National Film Registry. In 1998, it was ranked number 12 on the American Film Institute's list of the 100 best American films of the 20th century. In 2007, it was 16th on their 10th Anniversary list.