Hugh Jackman was originally set to play George Reeves, but pulled out of the project due to other commitments.
Benicio Del Toro was signed on to play the detective, but pulled out of the project due to other commitments.
Joaquin Phoenix auditioned for the role of Louis Simo, but Adrien Brody got it. This is the second time the two have auditioned for the same role. In The Village (2004), both men auditioned for the role of Lucius Hunt, with Phoenix getting the role.
George Reeves's biographer, actor Jim Beaver, served as historical consultant on this film and was offered a role. He was unable to accept due to conflicts with his "Deadwood" (2004) schedule. Coincidentally, two of his "Deadwood" (2004) co-stars, Molly Parker and Larry Cedar, do appear in the film.
The Alvis automobile George Reeves is shown washing in the film is an extremely rare model that was shipped to the location for use in the movie, as it is one of the few existing examples of the car Reeves actually owned.
Ben Affleck wears a pinkie ring and smokes with a cigarette holder in the film, just as George Reeves did in real life.
The film's producers were forced to shoot a new version of the opening credits of the TV "Adventures of Superman" (1952) when Warner Bros. refused permission for the actual opening credits to be used within the film.
George Reeves's agent, Gus Dembling, was combined in the film with the character of Reeves's manager, Arthur Weissman, who in actuality did not come into Reeves' life until much later than the film depicts.
The photo of the dead woman whose demise Louis Simo accuses E.J. Mannix of complicity in is actually the death-scene photo of actress Carole Landis.
The film was originally entitled Truth, Justice, and the American Way (after Superman's famous catchphrase). However, DC Comics (which owns the rights to the Superman character) refused to allow that. It also did not allow the Superman "S" insignia to be used in any of the trailers or promotional material of the film, but oddly enough allowed it to be in the actual movie.
The famous Hollywood sign originally read Hollywoodland, promoting a real estate project in the 1920s. The last 4 letters were removed in 1949.
Feature film debut for veteran TV director Allen Coulter.