Smallville is an American superhero television series developed by writer-producers Alfred Gough and Miles Millar, based on the DC Comics character Superman created by Jerry Siegel and Joe Shuster. The series was produced by Millar/Gough Ink, Tollin/Robbins Productions, DC Comics and Warner Bros. Television. Initially broadcast by the WB, the show premiered on October 16, 2001. After its fifth season, the WB and UPN merged to form The CW, the series' later United States broadcaster until its tenth and final season ended on May 13, 2011.

Smallville follows the coming-of-age adventures of teenage Clark Kent (Tom Welling) in his fictional hometown of Smallville, Kansas, before he formally becomes the Man of Steel. The first four seasons focus on the high school life of Clark and his friends, his complicated romance with neighbor girl Lana Lang (Kristin Kreuk), and his friendship with future nemesis Lex Luthor (Michael Rosenbaum). From season five onwards, Smallville ventures into Clark's early adult years, eventually focusing on his career alongside Lois Lane (Erica Durance) at the Daily Planet and introducing other DC comicbook superheroes and villains.

Before the series' production, Bruce Wayne, a drama series chronicling the young protagonist's journey toward Batman, was proposed first. Although that series failed to generate interest, it inspired the idea of a Superman origin story, which later became Smallville. Series developers Gough and Millar pitched their "no tights, no flights" rule to the president of Warner Bros. Television, reducing the Man of Steel to the bare moral essentials and examining what led Clark Kent to become the iconic superhero. After seven seasons with the show, Gough and Millar departed with little explanation. Smallville was primarily filmed in and around Vancouver, British Columbia, with local businesses and buildings substituting for Smallville locations. Most of the music for the first six seasons was composed by Mark Snow, who incorporated elements of John Williams's musical score from the Superman film series. In season seven, Louis Febre (who worked with Snow from the beginning) became the series' primary composer.

Smallville was generally positively received when it began. Former Superman star Christopher Reeve expressed approval for the series, making two guest appearances before his death. The pilot episode set a ratings record for a WB debut, with 8.4 million viewers. Over ten seasons the series averaged about 4.34 million viewers per episode, with season two the highest-rated at 6.3 million. By the end of its run, Smallville passed Stargate SG-1 as the longest-running North American science fiction series by episode count. Since its first season, the series received accolades ranging from Emmys to Teen Choice Awards. Smallville spawned a series of young adult novels, a DC Comics bimonthly comic-book, soundtracks and series-related merchandise. All ten seasons are available on DVD in regions 1, 2 and 4. After the series finale in 2011, the story resumed in comic-book form, with 22 issues of Season 11 from April 2012 to November 2013.