In an image released by 'Batman V Superman: Dawn of Justice' director Zack Snyder on his Twitter account, Momoa takes on the role of the King of Atlantis in a complete departure from the historic, and quite frankly wimpy, appearance of DC's Aquaman.
Aquaman - alter ego of Arthur Curry - is often the butt of comic book nerds' jokes as his powers are seen as being a bit useless. He can talk to fish and survive underwater, making him a bit rubbish when most of the evil-doers reside on land.
But you wouldn't say that to Jason Somoa's face now, would you?
The extent of Jason's role hasn't been made clear, but he'll be joining a star-studded cast of classic DC heroes, with Gal Gadot making an appearance as Wonder Woman and Ray Fisher tipped to play Cyborg. Ezra Miller has already been cast as The Flash for a separate movie, so he may well make an appearance here.
The phrase "Unite The Seven" shown on the tweeted picture could either be a reference to the seven seas, or to the seven members of the Justice League. It's been rumoured that Snyder may be attempting to flesh out the upcoming film with DC's big names to help the franchise rival Marvel in the cinema.
Aquaman will reportedly have his own movie in 2017, with Wonder Woman, The Flash and the entire Justice League tipped for films too.
Jason's appearance in this teaser picture doesn't seem to vary too much from his role as Khal Drogo in 'Game Of Thrones', with his huge size and imposing facial hair, but he's just about Aquaman-enough to make it work.
'Batman V. Superman: Dawn Of Justice' will star Ben Affleck, and is set for release on 26 March 2016.