HitFix had the scoop this weekend, writing that while Momoa had previously complained about being asked about the role, the media was on to something.
"While Warner Bros. hasn't made that announcement officially yet, HitFix can confirm that he will be playing the part, and that [director] Zack Snyder has already finalized his designs for the character so shooting can take place soon," the site said.
And that's not all. According to HitFix, while Momoa won't have much to do in "Batman vs. Superman," his small part will set in motion events that will eventually play out in the "Justice League" films.
" ... [W]hat we're hearing is that [Aquaman] is not pleased about the World Engine and what it did to the Indian Ocean [in 'Man of Steel']," writes HitFix about Aquaman's role in "Dawn of Justice."
Momoa ("Game of Thrones") joins a host of new superhero characters in the "Man of Steel" follow-up, including Batman (Ben Affleck) and Wonder Woman (Gal Gadot). Henry Cavill is returning as Superman.
"Batman vs. Superman" hits theaters on May 6, 2016.