Momoa, who portrays the titular future ruler of Atlantis, is wearing Aquaman's classic outfit, which features orange and green armor, as he swims underwater.
Heard, who stars as Aquman's love interest Princess Mera, looks ready for a fight as she stands in front of a group of soldiers riding sharks.
Kidman, who appears as Aquaman's mother Queen Atlanna, emerges from the ocean while holding a silver trident. Behind Atlanna is the lighthouse where she meets Aquaman's human father.
The character posters also highlight the various villains of the film including Patrick Wilson as Aquaman's half-brother King Orm, Yahya Abdul-Mateen II as ruthless mercenary Black Manta and Dolph Lundgren as King Nereus. Willem Dafoe as Atlantis advisor Vulko is also featured.
Aquaman, from director James Wan, is set to arrive in theaters on Dec. 21.
"The film reveals the origin story of half-human, half-Atlantean Arthur Curry and takes him on the journey of his lifetime -- one that will not only force him to face who he really is, but to discover if he is worthy of who he was born to be... a king," reads the synopsis.