Present in both movies
- Played By: Harry Hamlin (1981 version), Sam Worthington (remake)
- Action Dad: Becomes a father in the second movie, though he retired as a fisherman after his son's birth. He is thrust into action when danger emerges by the walls of Tartarus falling apart.
- Action Genre Hero Guy: Sports a highly modern-looking buzzk cut in the remake akin to modern soldiers and video game action heroes. He grows out a more curly hair similar to his 1981 incarnation.
- Adaptational Angst Upgrade: Perseus is a lot more gloomy and edgier in the 2010 due to his adoptive family being killed by Hades, as well as more disdainful and hostile to his divine heritage.
- Cain and Abel: He is the Abel to Ares' Cain in Wrath of the Titans.
- Child by Rape: In the remake, he was conceived this way when Zeus disguised himself as Danae's husband to sleep with her. Perseus is understandably pissed off when learning about his true heritage.
- Half-Human Hybrid: Half-human, half-Olympian to be precise.
- The Hero: In both versions of the movie, though he is a little darker and edgier in the remake.
- Super Strength: In Wrath of the Titans, he displays enough physical force to restrain a chimera and fight hand-to-hand with Ares, a God (something which his mythological counterpart never did).
- Adaptational Badass: In Wrath of the Titans, Andromeda becomes a Lady of War after being a Distressed Damsel in the previous movies and original myths.
- Adaptational Dye Job: Goes from a blonde to a brunette in the remake to back to being a blonde for the sequel.
- Demoted to Extra: While she was originally Perseus' love interest in the original myths and a relatively bigger role in the 1981 movie, she has very little screentime in the remake and isn't involved romantically with Perseus in anyway.
- Promoted to Love Interest: Inverted in the remake. Despite being Perseus' wife in both the original movie and the original myths, they don't get together in the 2010 movie. The sequel rectifies this.
- Adaptational Jerkass: Downplayed in the remake; he explicitly conceived Perseus as part of a punishment to Acrisius by seducing his wife whereas he never done such thing in the original movie. The reason this is downplayed is because its in no way out of character for Zeus in regards to the original myths.
- Cain and Abel: The Abel to Hades' Cain in the remake.
- Divine Assistance: He insists in helping Perseus in both versions by giving him divine weapons and Pegasus, even in the remake where he is more antagonistic.
- Deus ex Machina: Almost literally in the 1981 movie; when Perseus succumbs to weariness as the deadline to release the Kraken approaches, he secretly restores his strength while none of the gods are looking just in time for him to save the day.
- Grandpa God: When played by Laurence Olivier, that is.
- Powered by a Forsaken Child: Zeus is captured in Wrath of the Titans and used by Hades as a battery to release Kronos from his prison.
- Took a Level in Kindness: He is a lot more humble in asking for Perseus' help in Wrath of the Titans. Being struck with mortality does wonders to one's social skills.
- Played By: Stop-motion (1981), Natalia Vodianova (remake)
- Adaptational Attractiveness: She looks hideous in the original movie, whereas she is played by Russian supermodel Natalia Vodianova in the remake, retaining her beautifiul face... Unless when she uses her powers.
- Adaptational Badass: In both versions, Medusa becomes something of an slasher horror monster that kills Perseus' companions one by one. She is even more badass in the remake where she gains Super Strength.
- Ambiguously Evil: Medusa never speaks, and one could say that she's doing little more than defending her home against trespassers. Viewers can make their own conclusions.
- Archer Archetype: Holds a bow and arrow using it to literally shatter her victims after they were turned to stone.
- Snake People: She has the lower half of a snake.
- Taken for Granite: Anyone that looks into her gaze gets turned into stone instantly. It still works even after her death.
- Played By: Neil McCarthy (1981), Jason Flemyng (remake)
- An Arm and a Leg: He loses one of his hands in both versions.
- Baleful Polymorph: He was man turned into a near-demonic monstrosity by Zeus.
- Canon Foreigner: There was no Calibos or any similar figure in Perseus' original myth.
- Composite Character: In the remake, he is combined with Perseus' grandfather Acrisius.
- The Dragon: To Hades in the 2010 remake.
- Dying as Yourself: He reverts to his human form after being fatally wounded by Perseus.
- Evil Poacher: In the 1981, what made Zeus curse him with his beastly form was Calibos' overhunting the Wells of the Moon and killing all his sacred flying horses, leaving only Pegasus alive.
- Expy: He was seemingly based on the character Caliban from The Tempest.
- Related in the Adaptation: In the 2010 remake, not only isn't Thetis' son, but due to being combined with Acrisius, he is Danae's husband rather than her father.
A colossal sea monster of incredible power and said to be the last of the Titans.
- Adaptational Name Change: The monster sent to devour Andromeda and destroy her city was originally named Cetus/Ketos. The creators didn't knew what the Kraken was, but renamed him because thought it sounded cool.
- The Dreaded: At least in the remake, its said even the gods themselves fear him.
- Eldritch Abomination: An incredibly huge monster older than the entire human race that sleeps on the bottom of the ocean, it killed the Titans. Its design in the remake is even more alien.
- The Juggernaut: There is no mortal powerful enough to defeat it by themselves. The only thing capable of destroying him is Medusa's head.
- Kraken and Leviathan: Of course.
- Taken for Granite: The only way to destroy him using the head of Medusa, followed by Literally Shattered Lives.
- Sadly Mythtaken: The Kraken was not from Greek mythology, and rather originated from Norse legends.
Present in the 1981 version
- Played By: Maggie Smith
- Ascended Extra: Relative to the myths, Thetis was a minor figure that unwittingly precipitated the Trojan War (it was in her wedding that Eris gave her infamous Apple of Discord). Here she is turned into a full-blown antagonist and a thorn on the heroes' side.
- Big Bad: For the original movie, she is responsible for causing misery and ruin to Joppa in response to Calibos' curse.
- Mama Bear: Towards her son Calibos, though this is played negatively since she ended up spoiling and turning him into a depraved individual.
- Misplaced Retribution: After her son is punished for his own crimes, she is unable to retaliate against Zeus but instead places a curse on her son's former betrothed Andromeda, who is innocent of any wrong doing. She does it again when she sentences Andromeda to be sacrificed by the Kraken after her mother Cassiopeia says she is more beautiful than Thetis.
An mechanical owl created by Hephaestus and based on Athena's pet owl of the same name.
- Cute Owl: Its robotic design is very adorable and serves as comic relief.
- Intelligible Unintelligible: Its only capable of communicating in clicks and whistles and the only one capable of perfectly understanding it is Perseus. Justified by the fact that it is a gift from the goddess Athena.
- Robot Buddy: To Perseus, though its a clockwork example.
Present in the remake version
- Played By: Gemma Arterton
- The Ageless: She was cursed by immortality and is unable to age. She can still be killed normally.
- Back from the Dead: She is resurrected at the end of the movie by Zeus as a reward for saving everyone.
- Cursed with Awesome: Her immortality, at least in Perseus' opinion. Io is less than pleased explaining it pretty much is a curse when all her loved ones grow old and die while she remains young.
- Missing Mom: To her son Helius, having died a long time ago.
- Promoted to Love Interest: Io was Perseus' very distant ancestor, but in the 2010 remake, she becomes his love interest instead of Andromeda.
- Played By: Ian Whyte
- The Beastmaster: He is able to tame the giant scorpions attacking Perseus and the Argive soldiers.
- Canon Foreigner: There were never any genies encountered in Greek mythology and they were created solely for the 2010 movie.
- Humanoid Abomination: While definitely an heroic example, him and his tribe look very creepy, are implied to be formerly human themselves and use wood materials to rebuild themselves. He is also immune to Medusa's petrifying gaze.
- Our Genies Are Different: They appear as black-colored humanoid creatures with bright blue eyes that use blue fire magic that seems organic based (they tame scorpions, heal the hero and are claimed to rebuild themselves of wood).
- Played By: Ralph Fiennes
- Big Bad: For the 2010 movie, he takes over Thetis' role and wants to wreck hell on Earth.
- Cain and Abel: The Cain to Zeus' Abel. Subverted in the second movie when they set aside their differences.
- Dark Is Evil: He is the God of the Dead and a villain in the two remake movies.
- The Dreaded: Unlike other gods who derive their power from humans' worship, Hades draws his strength from their fear of death, which is pretty commonplace.
- Demoted to Dragon: Goes from Big Bad in the first movie to agreeing to release Kronos in exchange for preserving his immortality.
- Everybody Hates Hades: He is the main villain due to being tricked out in taking the underworld as his domain while Poseidon took the seas and Zeus had the earth and heaven.
- HeelFace Turn: Pulls one at the end of Wrath of the Titans.
- Karma Houdini: Downplayed. He redeems himself by helping fight against Kronos during the climax of Wrath and is the last surviving Olympian at the end. With that said, he lost all of his powers and immortality, and is now stuck with walking among humans.
- Last of His Kind: He is the last still living Olympian left at the end of Wrath and even then he is immortal.
- The Quisling: In the second movie, he is willing to sell out what little remains of Olympus and all of humanity to Kronos so he can keep his immortality.
- Played By: Edgar Rámirez
- Cain and Abel: The Cain to Perseus' Abel in Wrath of the Titans.
- The Brute: He is more hands on in physical combat than the other gods and personally throws down with Perseus in their fight.
- War God: He is Ares, after all.
- The Resenter: Towards Perseus, whom he thinks is Zeus' favorite child.
- The Unfavorite: Considers himself one to Zeus.
Lord of the Titans and the father of Zeus, Poseidon and Hades.
- Big Bad: In Wrath of the Titans.
- Eldritch Abomination: He has the power to destroy the Earth if he is ever unleashed from Tartarus and its said that he was so mighty that the gods needed the help of the Kraken (another Eldritch Abomination) to defeat him, meaning that he is even more terrible than the Kraken.
- Magma Man: Manifests himself as a humanoid being made of fire and lava.
- Sealed Evil in a Can: Tartarus serves as his prison