Sunset Boulevard (styled in the main title on-screen as SUNSET BLVD.) is a 1950 American black comedy film noir directed and co-written by Billy Wilder, and produced and co-written by Charles Brackett. It was named after a major street that runs through Hollywood, the center of the American film industry.

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 leading silent-film actors 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, and in 2007, it was 16th on their 10th Anniversary list.