Alexander Joseph "Lex" Luthor is a fictional character and supervillain in The CW's Arrowverse franchise of TV series, first introduced in the 2017 episode "Luthors", of the Supergirl, based on the character of the same name, created by Jerry Siegel and Joe Shuster, and was adapted for television in 2017 by Glen Winter and Greg Berlanti. The character of Lex Luthor is the nemesis of Superman, and is only the fourth time that the character has been adapted to a live action television series.