- Perseus: The demigod son of Zeus, who is on a quest to save Andromeda and defeat the Kraken.
- Andromeda: The princess of Argos, who is sacrificed to the Kraken in order to appease the gods.
- Io: A priestess of the god Apollo who is revealed to be the daughter of Zeus.
- Zeus: The king of the gods, who is Perseus' father.
- Hades: The god of the underworld, who is the main antagonist of the film.
- Poseidon: The god of the sea, who is also Perseus' uncle.
- Athena: The goddess of war and wisdom, who helps Perseus on his quest.
- Apollo: The god of music, healing and divination, and has a romantic relationship with Io.
- Hephaestus: The god of fire and blacksmithing.
- Ares: The god of war, who is defeated by Perseus.
- Calibos: A deformed cyclops who is the son of Poseidon and an acolyte of Hades.