Season one of Smallville, an American television series developed by Alfred Gough and Miles Millar, began airing on October 16, 2001, on The WB television network. The series recounts the early adventures of Kryptonian Clark Kent as he adjusts to his developing superpowers in the fictional town of Smallville, Kansas, during the years before he becomes Superman. The first season comprises 21 episodes and concluded its initial airing on May 21, 2002. Regular cast members during season one include Tom Welling, Michael Rosenbaum, Kristin Kreuk, Annette O'Toole, John Schneider, Sam Jones III, Allison Mack, and Eric Johnson.

The season's stories focus on Martha and Jonathan Kent's (O'Toole and Schneider) attempts to help their adopted son Clark (Welling) cope with his alien origin and control his developing superhuman abilities. Clark must deal with the meteor-infected individuals that begin appearing in Smallville, his love for Lana Lang (Kreuk), and not being able to tell his two best friends, Pete Ross (Jones III) and Chloe Sullivan (Mack), about his abilities or his origins. Clark also befriends Lex Luthor (Rosenbaum) after saving Lex's life. The season also follows Lex, as he tries to assert his independence from his father, Lionel Luthor (John Glover).