Many series actors and guest stars have had roles in previous film and television versions of the Superman comic: Christopher Reeve (Dr. Virgil Swann) played Superman in Superman (1978) and its three sequels; Terence Stamp (Jor-El) played the Phantom Zone villain General Zod in Superman II (1980); Annette O'Toole (Martha Kent) played Lana Lang in Superman III (1983); Dean Cain (Dr. Curtis Knox) played Clark Kent in "Lois & Clark: The New Adventures of Superman" (1993); Helen Slater (Lara, Clark's mother) played Kara/Supergirl in Supergirl (1984). Lynda Carter (Moira Sullivan, Chloe's mother) played Wonder Woman/Diana Prince in "Wonder Woman" (1976) ("Wonder Woman" is, like Superman, a DC Comics superhero). Jeannot Szwarc, who has directed 9 episodes (as of 2007) also directed Supergirl (1984). Margot Kidder (Bridgette Crosby) played Lois Lane in Superman (1978) and its three sequels.
The Smallville High Student Newspaper that Clark and Chloe write for is named for Glenville High School's Student Newspaper "The Torch" which Superman creator Jerry Siegel wrote for when he was a student there.
In each episode Clark can be seen wearing any one of, or a combination of red, yellow and blue; the colours he will one day don as Superman.
Contains frequent in-joke references to the Superman mythos in various episodes.
Chloe and Whitney were created specifically for the show (they were never mentioned in the Superman comics). However, in 2003, DC Comics announced that Chloe would be introduced into the Superman comics.
Lex Luthor's mansion is the same mansion used in X2 (2003)
Belle Reve is the name of the estate that Blanche and Stella DuBois come from in Tennessee Williams's "A Streetcar Named Desire". Throughout the play, Blanche gradually becomes insane. In "Smallville" (2001), Belle Reve is the name of a mental hospital. In DC Comics, Belle Reve is the name of a federal prison for super-villains; it is located in Louisiana.
Jensen Ackles, who plays Jason Teague in Season 4, was the second choice to play Clark Kent. If Tom Welling had not accepted the part, the role would have gone to him
The name of one of the Kryptonian baddies from season 5 is named Nam-Ek, the same name of the race of aliens come to earth (the race of aliens that Piccolo hails from) in the anime Dragonball Z. Nam-Ek is also the name of one of the Phantom Zone criminals in the DC Comics Superman titles, first appearing in Superman #282 (December 1974).
After the fifth season, the show was picked up by The CW because The WB merged with UPN to form The CW.
Kristen Bell auditioned for the role of Chloe Sullivan.
Lana and Chloe's dorm room number is 222, a reference to "Room 222" (1969).
Although he plays the lead character, Tom Welling has admitted in interviews that he is not a fan of the Superman comic books.
'Milo Ventimiglia (I)' originally auditioned for the role of Clark Kent. Although the role went to Tom Welling, the producers at The WB liked him so much they gave him the role of Jess on "Gilmore Girls" (2000). Ventimiglia now plays a different comic book-style superhero on "Heroes" (2006/II).