The sequel would have centered around Brainiac who would have originally been from Krypton. He would have followed Superman back to Earth from the remnants of Krypton during his five year trip. Also, the bank robber who shot Superman in the eye around the middle of the first film would turn out to be John Corben, a.k.a. Metallo for the sequel.
- Brandon Routh as Kal-El/Clark Kent/Superman
- Kate Bosworth as Lois Lane
- Kevin Spacey as Lex Luthor
- Sam Huntington as Jimmy Olsen
- Frank Langella as Perry White
- Tristan Lake Leabu as Jason White
In February 2006, four months before the release of Superman Returns, Warner Bros. announced a mid-2009 theatrical release date for a sequel, with Bryan Singer reprising his directing duties. Brandon Routh, Kate Bosworth, Kevin Spacey, Sam Huntington, Frank Langella, and Tristan Lake Leabu were to reprise their roles. Due to his commitment, Singer dropped out of directing a remake of Logan's Run and an adaptation of The Mayor of Castro Street. Although Superman Returns received mostly positive reviews, Warner Bros. and Legendary Pictures were disappointed by the film's box office return. Warner Bros. President Alan F. Horn explained that Superman Returns was a very successful film, but that it "should have done $500 million worldwide. We should have had perhaps a little more action to satisfy the young male crowd." Singer reacted incredulously to the studio complaints, saying, "That movie made $400 million! I don't know what constitutes under-performing these days ..." $175 million was the maximum budget Warner Bros. was projecting for the sequel, as Superman Returns cost $209 million.
Filming for the Superman Returns sequel was to start in mid-2007, before Singer halted development in favor of Valkyrie. Filming was then pushed to March 2008, but writers Dougherty and Dan Harris left in favor of other career opportunities. The 2007–2008 Writers Guild of America strike pushed the release date to 2010. Singer still listed the sequel as a priority in March 2008, saying that the film was in early development. Routh expected filming to begin in early 2009. Paul Levitz, president of DC Comics, expected Routh to reprise the title role from Superman Returns before his contract for a sequel expired in 2009. However, with Warner Bros. deciding to reboot the film series, Singer dropped out in favor of directing Jack the Giant Killer, and a film adaptation of Battlestar Galactica. "Superman Returns didn't quite work as a film in the way that we wanted it to," Warner Bros. President of Production Jeff Robinov reflected in August 2008. "It didn't position the character the way he needed to be positioned. Had Superman worked in 2006, we would have had a movie for Christmas of this year or 2009. Now the plan is just to reintroduce Superman without regard to a Batman and Superman movie at all."