"Lux Radio Theater" broadcast a 60 minute radio adaptation of the movie on September 17, 1951 with Gloria Swanson and William Holden reprising their film roles.

Darryl F. Zanuck, Olivia de Havilland, Tyrone Power and Samuel Goldwyn all refused to allow their names to be used in the film, but Billy Wilder decided to use Zanuck's and Power's names anyway. Oddly enough, the reclusive Greta Garbo granted permission to use her name, though when she saw the film itself she was sorry she had done so. She felt that Wilder used her name in a past-tense context, and she was offended.

Hedda Hopper and Buster Keaton, who make cameos as themselves in the movie, both died on the same day: February 1, 1966.

Hedda Hopper: at the top of the stairwell as Norma descends toward the cameras.

Mae West rejected the role of Norma Desmond because she felt she was too young to play a silent film star. Mary Pickford rejected it because she was afraid it would destroy her wholesome image.

Montgomery Clift quit the production because he was, like the character of Joe, having an affair with a wealthy middle-aged former actress - Libby Holman. She pressured him to back out of the role.

Montgomery Clift, signed to play the part of Joe Gillis, (on advice of Libby Holman) broke his contract just two weeks prior to the start of shooting. Billy Wilder quickly offered the role to Fred MacMurray, who turned it down because he didn't want to play a gigolo. Marlon Brando was considered, but the producers thought he was too much of an unknown as a film actor. Gene Kelly was then approached, but MGM refused to loan him out. Reluctantly, Wilder met with William Holden, whose films to that time had not impressed Wilder (Holden's films of the 1940's were decidedly mediocre). They eventually worked together on several films and became longtime friends. It was largely from his association with Wilder that Holden would enjoy the greatest acting successes of his career in the 1950's.

Cecil B. DeMille agreed to do his cameo for a $10,000 fee and a brand-new Cadillac. When Billy Wilder went back to him later to secure a close-up, DeMille charged him another $10,000.

Cecil B. DeMille had a pet name for Gloria Swanson - "Young Fellow" - because he said she was braver than any man. Charles Brackett and Billy Wilder retained the term of endearment for the scene in which DeMille greets Norma Desmond at the door of the soundstage.

Cecil B. DeMille: at the studio during Norma's visit.

H.B. Warner, Buster Keaton, Anna Q. Nilsson: in the card game scene.

Billy Wilder and Charles Brackett met with Greta Garbo and tried to convince her to make a comeback for the role of Norma Desmond. Garbo declined the offer.

Billy Wilder and Charles Brackett's 17th and final screenplay collaboration. After the completion of "Sunset Boulevard," Wilder shocked his longtime collaborator by announcing that he wished to dissolve their partnership. The two men never worked together again.

Billy Wilder originally wanted another silent star, Pola Negri, to take the part of Norma Desmond. Upon telephoning her, however, Wilder found that Negri's Polish accent, which had killed her career, was still too thick for such a dialog-heavy film.

Billy Wilder wanted a fresh face for the part of Betty Schaefer. The part was only Nancy Olson's third film appearance.

Billy Wilder was actually more friendly with the other leading gossip columnist of the day, Louella Parsons. However, he knew that her arch-rival Hedda Hopper had trained as an actress and would therefore be more convincing onscreen.

William Haines, along with fellow silent screen veterans Buster Keaton and Anna Q. Nilsson, was approached to play one of Gloria Swanson's bridge partners. Swanson herself reportedly asked him to do it. Haines declined and fellow screen veteran H.B. Warner took the part.

Gloria Swanson almost considered rejecting the role of Norma Desmond after Billy Wilder requested she do a screen test for the role. Her friend George Cukor, who initially recommended her for the part, told her, "If they want you to do ten screen tests, do ten screen tests. If you don't, I will personally shoot you." Swanson agreed to the audition, and won the role.

Gloria Swanson played her final descent on the staircase - and into madness - barefoot, as she was terrified of tripping if she'd worn high heels. Since her part required her to gaze at the newsreel cameramen and "fans" (the waiting police) gathered in the foyer below, she couldn't watch where she placed her feet. She burst into tears upon completion of the scene.

Erich von Stroheim dismissed his participation in this film, referring to it as "that butler role."