Jason Momoa returns as Arthur Curry in a sequel the actor pitched to Warner Bros.
The story will follow Aquaman as he makes "an uneasy alliance" to protect Atlantis and the rest of the world from "irreversible devastation."
"After we finished the first one I went into [Warner Bros.] with my writing partner, I had dreamed up the second one, and we went in and we pitched the idea," Momoa said on "The Drew Barrymore show.
Director James Wan and screenwriter David Leslie Johnson-McGoldrick finished up the script after Momoa's first draft.
Patrick Wilson, Amber Heard, Yahya Abdul-Mateen II, Randall Park, Dolph Lundgren, Temuera Morrison, and Nicole Kidman will also reprise their roles in the sequel.