Superman - Supporting cast

Clark Kent, Superman's secret identity, was based partly on Harold Lloyd and named after Clark Gable and Kent Taylor. Creators have discussed the idea of whether Superman pretends to be Clark Kent or vice versa, and at differing times in the publication either approach has been adopted. Although typically a newspaper reporter, during the 1970s the character left the Daily Planet for a time to work for television, whilst the 1980s revamp by John Byrne saw the character become somewhat more aggressive. This aggressiveness has since faded with subsequent creators restoring the mild mannerisms traditional to the character.

Superman's large cast of supporting characters includes Lois Lane, perhaps the character most commonly associated with Superman, being portrayed at different times as his colleague, competitor, love interest and/or wife. Other main supporting characters include Daily Planet coworkers such as photographer Jimmy Olsen and editor Perry White, Clark Kent's adopted parents Jonathan and Martha Kent, childhood sweetheart Lana Lang and best friend Pete Ross, and former college love interest Lori Lemaris (a mermaid). Stories making reference to the possibility of Superman siring children have been featured both in and out of mainstream continuity.

Incarnations of Supergirl, Krypto the Superdog, and Superboy have also been major characters in the mythos, as well as the Justice League of America (of which Superman is usually a member). A feature shared by several supporting characters is alliterative names, especially with the initials "LL", including Lex Luthor, Lois Lane, Linda Lee, Lana Lang, Lori Lemaris and Lucy Lane, alliteration being common in early comics.

Team-ups with fellow comics icon Batman are common, inspiring many stories over the years. When paired, they are often referred to as the "World's Finest" in a nod to the name of the comic book series that features many team-up stories. In 2003, DC began to publish a new series featuring the two characters titled Superman/Batman.

Superman also has a rogues gallery of enemies, including his most well-known nemesis, Lex Luthor, who has been envisioned over the years in various forms as either a rogue scientific genius with a personal vendetta against Superman, or a powerful but corrupt CEO of a conglomerate called LexCorp. In the 2000s, he even becomes President of the United States, and has been depicted occasionally as a former childhood friend of Clark Kent. The alien android (in most incarnations) known as Brainiac is considered by Richard George to be the second most effective enemy of Superman. The enemy that accomplished the most, by actually killing Superman, is the raging monster Doomsday. Darkseid, one of the most powerful beings in the DC Universe, is also a formidable nemesis in most post-Crisis comics. Other enemies who have featured in various incarnations of the character, from comic books to film and television include the fifth-dimensional imp Mister Mxyzptlk, the reverse Superman known as Bizarro and the Kryptonian criminal General Zod.