After the 15th episode of Season 10 airs, Smallville will take the crown (and the Guinness World Record) for being the longest consecutively running Sci-Fi television serial of all time (10 years without a break). Stargate SG-1 (1997) holds that title with 213 episodes, which Smallville will supersede by 5 episodes by the end of Season 10 (it's final season). Doctor Who however holds the record for the longest running Sci-Fi show in the world, running from 1963 to 2010, with another series starting in 2011, totalling over 700 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.
Since the start of the "Superman" comic book, there has been an abundance of characters with the initials "L.L.," including Lex Luthor, Lana Lang, Lois Lane, Lori Lemaris, Lucy Lane, Linda Lee, etc. "Smallville" continued that naming tradition with several of the characters created for the show, including Lex's parents, Lionel and Lillian Luthor, his brother, Lucas Luthor, and Lana's parents, Laura and Lewis Lang.
Originally, Tollin/Robbins Productions were planing to do a show that followed the story of a young Bruce Wayne before he became Batman. Since Warner Bros. Studios had decided to do Batman Begins (2005) and didn't wanted the film to compete with a television show, Tollin/Robbins Productions suggested Peter Roth, President of Warner Bros Televisión, to develop a show about a young Clark Kent, which later became "Smallville".
Although he plays the lead character, Tom Welling has admitted in interviews that he is not a fan of the Superman comic books. However, Welling believed his lack of knowledge on the character mythology actually helped his portrayal of Clark.
Twin brothers Shawn Ashmore and Aaron Ashmore both appear in the show throughout the seasons. Shawn as Eric Summers in Leech (Season 1) and Asylum (Season 3), and then Aaron as Jimmy Olsen from Season 6 on.
With both Chloe and Lana, Clark is tricked into revealing his abilities in front of them. In Season 4, Alicia sets things up so that Clark will show off his abilities for Chloe, and in Season 6, Lana sets things up so that Clark uses his abilities while she secretly watches.
Actors Tom Welling, Allison Mack, Michael Rosenbaum, John Schneider, and Justin Hartley are the only actors to ever appear on the show, who also directed episodes of it as well. Although they did not direct the same amount of course since Welling has directed seven episodes; Mack has directed two; and Rosenbaum, Schneider, and Hartley all directed one episode each during the show's 10 year run.
The character of Tess Mercer, aka Lutessa Luthor (Cassidy Freeman), was created to fill the spot left by Michael Rosenbaum's Lex Luthor in Season 8. Tess is an amalgam of the most infamous of Lex Luthor's female counterparts from various sources; Miss Tessmacher (Valerie Perrine) in "Superman: The Movie", Mercy Graves (Lisa Edelstein) in "Superman: The Animated Series", and Contessa Del Portenza from the comic book series.
'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).
The Smallville High Student Newspaper that Clark and Chloe write for is named "The Torch," after the student newspaper at Glenville High School in Cleveland, Ohio. Superman creators Jerry Siegel and Joe Shuster worked together on the Glenville Torch while they were students.
Margot Kidder's character, Bridgette Crosby, was meant to become the primary villain of Season 4. After Christopher Reeve's untimely death in 2004, the show's producers decided to incorporate the death of the legendary actor into the plot as his character Virgil Swann was killed off screen. Kidder was not happy with this decision, feeling the producers were capitalizing on the actor's passing. Thus, she backed out of her commitments. As a result, the character of Genevieve Teague, as played by Jane Seymour, was created to fill in as the central big bad for the remainder of the season. Ironically, Christopher Reeve played a romantic love interest opposite both Margot Kidder and Jane Seymour; Kidder in Superman (1978) and Seymour in Somewhere in Time (1980).
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.
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).
The rooms in the show will usually have something that is Red, Blue and Yellow this can include wall color, furniture etc. Also there are times where the coloring in the room (such as the Smallville Medical Center) that the colors of Green and Purple are used (Lex Luthor's old colors from the Superman comics).
The trivia items below may give away important plot points.
The first and last shots of Michael Rosenbaum (as Lex Luthor) are identical. In "Pilot", Lex turns to the camera after stepping out of his car at the "LexCorp" plant, and in "Finale Part II", President-elect Lex Luthor turns around to face the press cameras in an identical manner.
In the 'Sacred' episode of Season three, when Virgil Swan's death is announced you, you can hear the reporter say, "... and now to our on scene reporter, Tom Flores." Tom Flores is the associate producer of "Smallville".