Early promotional literature for this series noted that Clark Kent would be called Superboy, as in the comics. However, a recent court ruling awarding copyright to that specific character to creator Jerry Siegel's family prompted Warner Brothers to change the premise by having Clark's superhero identity be simply a young Superman.
This series was originally developed because of Cartoon Network's desire to have a Superman-centric series to coincide with the movie Superman Returns (2006) and Superman as part of the Legion worked for them. When Cartoon Network passed on the show, Kids WB! stepped in and they, too, wanted a Superman-centric series with Superman fresh out of Smallville, learning to be Superman.
The written language in the Legion's time is called Interlac.
A bulk of Legion's animation was done at Korea's Dong Woo and Lotto studios.
Saturn Girl in this series has telekinetic and telepathic powers. In all comic book iterations, the character, like most inhabitants of Titan, has only telepathy.