Ulysses and his crew onboard the Odysseus spaceship.
The series' main protagonist, and the captain of the Odysseus. As an ambassador from Earth in the 31st century, he achieved the Solar Peace, putting an end to a galactic conflict on the planet of Troy, before becoming the subject of the Olympian gods' revenge. He is brave, noble, determined, and will stop at nothing to overcome the conditions imposed upon himself and his companions.
Named "Ulysse" in the French version.
- '80s Hair: Sports a glorious mulet. It must have become a thing again one millennia and then some after the 1980s (the show was made at the start of that decade in Real Life).
- Ace Pilot: He is a damn good pilot with the small vessels of the Odysseus.
- Adaptational Nice Guy: Classical Mythology Ulysses was extremely cunning (much more than him), sneakily enabled the Achaeans to finish The Trojan War through Rape, Pillage, and Burn and bloodily killed all of Penelope's suitors by himself, among many other very Anti-Hero things (by modern standards that is). This version of Ulysses is The Hero, is undeniably a Nice Guy, found a peaceful resolution to the space Trojan War and is The Fettered and a Martial Pacifist.
- Adult Fear: Considering the fact that he finds himself alone against all-powerful cosmic entities with only his beloved son to help (plus an alien girl and a small robot), it's only natural that he fears for his son's life (plus that of Yumi as well).
- Ambadassador: He was ambassador / space peace treaty-maker during the space version of The Trojan War, yet he never hesitates to face down the assorted dangers the gods of Olympus throw in his path.
- Badass Beard: Ulysses is bearded, and has the badassery to match.
- Badass Cape: Wears a long white cape, and surely looks badass with it.
- Badass Mustache: In addition to the beard.
- Badass Normal: Considering he's basically going up against the gods themselves, other various Cosmic Entities, magicians and the like... completely alone with the help of only two children, a small robot and his ship's technologies.
- Catchphrase: Has one in French: "Par la grande Galaxie!" ("By the great Galaxy!") when he's surprised.
- Combat Pragmatist: In "Phantoms from the Swamp" the Monsters of the Week are mud creatures that can turn themselves into likenesses of Ulysses and his crew. It turns out they can also copy his weapons but not his shield since "it's transparent." Once he figures this out he stops trying to sword fight and just shoots them from a distance since they have no defense against that.
- Comm Links: The red chest insignia he wears to hold his cape together on his sky blue Latex Space Suit allows him to communicate with Shyrka and the kids.
- Cool Sword: Ulysses' Laser Blade, blatantly inspired by the lightsabers of Star Wars, although it doesn't seem to be able to cut through anything unlike the lightsabers of Star Wars (then again, most of Ulysses' enemies are equipped/empowered by the gods, so go figure). The hilt can be used as a blaster gun.
- Determinator: He's going up against the gods themselves with no help except for a computer, two preteens and a small robot. He'd kind of have to be.
- A Father to His Men: He cares deeply about his crew.
- The Fettered: He's an Ideal Hero, Martial Pacifist and so on.
- Good Is Not Dumb: Ulysses might be slightly naive at times, but he's smart enough to always overcome the odds in his favor.
- Hero Protagonist: He's both The Hero and The Protagonist.
- Ideal Hero: Good luck finding a single moral flaw in his character.
- Identical Grandson: Played with. 31st century Ulysses and the original Ancient Greece Ulysses (and both Telemachus) are confused for each other, but their loved ones can tell the difference fairly easily.
- Incorruptible Pure Pureness: Ulysses is tempted many times into choosing an easier way to get back to Earth (usually by having to let his companions behind) by the gods throughout the series, yet he always chooses to stay and never abandons his companions.
- Jet Pack: Ulysses' Utility Belt allows him short flights and hovering.
- Latex Space Suit: He's got two versions. A brown casual one when onboard the Odysseus, and a sky blue when exploring worlds and piloting ships.
- Looks Like Jesus: Justified in that in this version, Ulysses is a Messianic figure of sorts.
- Luckily, My Shield Will Protect Me: He uses an energy shield combined with his Laser Blade, making him a 31st century version of ancient world warriors, basically.
- The Magnificent: The gods nickname him "Ulysse aux mille ruses" in French ("Ulysses of a thousand tricks").
- Manly Tears: In the episode "Calypso", he almost sheds a tear.
- Martial Pacifist: He only resorts to using violence when he has no other choice, usually to defend himself.
- The Men First: The gods often tempt him with an easy shortcut to get back to Earth with the condition of leaving his crew behind. He never accepts it out of loyalty to them.
- Nemean Skinning: Referenced in the design of his spacesuit's helmet.
- Nice Guy: Noble at heart, polite, compassionate, helpful, Friend to All Children... you name it.
- Papa Wolf: Ulysses will do anything to protect or save Telemachus. And Yumi as well, since she has become an adoptive daughter of sorts.
- The Punishment: Condemned by the gods to wander in the unknown in the galaxy of Olympus after destroying the Cyclops.
- Undying Loyalty: He is loyal to his crew, no matter how the gods tempt him into abandoning them.
The son of Ulysses and second in command of the Odysseus. Very beautiful, courageous, adventurous, level headed and a skilled pilot.
Named "Télémaque" in the French version.
- Adaptational Badass: The Classical Mythology Telemachus didn't follow his father into The Trojan War nor did he take part to Ulysses' perilous journey (in The Odyssey). This Telemachus accompanies his father through virtually every dangerous situation they have to confront, and finds crafty solutions aplenty to help win the day.
- Adaptational Nice Guy: Much like his father, his mythical counterpart had blood on his hands. This one doesn't.
- Bishōnen: He's a Pretty Boy with androgynous/"feminine" physical traits. Add to that the French version in which Jackie Berger, a woman, replaced Fabrice Josso to voice him sometimes.
- Brats with Slingshots: Some of his pranks involve his slingshot.
- Determinator: He's as determined as his father to get through the obstacles the gods of Olympus put in their path.
- Hair of Gold, Heart of Gold: He is made of this trope. He has blond hair, he's pure in heart and always willing to help.
- Nice Guy: He's as noble of heart as his father.
- The Prankster: He likes to prank Nono sometimes.
- Suffer the Slings: His Weapon of Choice is a high-tech slingshot that shoots energy balls.
A blue-skinned humanoid alien girl from the white planet, Zotra. She is the younger sister of Numinor and possesses telepathic powers. She is saved from being sacrificed to the Cyclops, along with Telemachus and her older brother, by Ulysses. Although physically very frail, she is very intelligent and courageous, and exhibits psychic and even telekinetic powers.
Named "Thémis" in the French version.
- Animal Eyes: Zotrians have cat-like slanted eyes with a vertical slit for a pupil.
- Big Brother Instinct: Unusually for the trope, it's Little Sister Instinct. Her older brother Numinor spends most of the series in the inanimate state the gods cursed Ulysses' crew with, so she vows to protect him during the perilous journey through the Olympus and worries for him whenever the dangers the Odysseus faces also directly threaten the inanimate crew.
- The Cutie: She's the cutest, sweetest and most lovable protagonist of the series.
- Graceful Ladies Like Purple: Her outfit is mostly purple. And she surely is graceful.
- Magical Flutist: She plays a mystical melody on a flute in the episode "The Sirens" after hearing said melody in a dream. A sarcophagus is found, and she finds out the melody opens it. It proves to be useful as a Brown Note against the Sirens and their petrifying metal tentacle (in a Snake Charmer way) later on.
- Mystical White Hair: Yumi is a telepath and she's got white hair.
- Nice Girl: She has a heart of gold.
- Pointy Ears: She has pointy ears, like all Zotrians.
- Psychic Link: She has a strong psychic link with her brother. She can instantly sense when he is awakened for instance, even when she can't see him.
- Rapid Aging: She ages rapidly while being prisoner in the Room of Seasons in the realm of Chronos. Ulysses reverses the effect with Chronos' universal clock.
- The Smurfette Principle: She's the only female main character.
- Telepathy: She has telepathic powers.
The small red robotic companion of Telemachus, given to him by Ulysses as a birthday present. He is rather shy, but can be relied upon in a crisis. He is skilled at machinery repair and possesses tremendous physical strength, and he's also fond of eating nuts and nails.
- Butt-Monkey: He's often the butt of Telemachus' pranks.
- Fingerless Hands: He has mitten-like hands.
- Kid-Appeal Character: He has a very toyetic appearance (well, he is a toy In-Universe to begin with), he's goofy and adorable.
- Long Neck: He is able to stretch his neck to great lengths.
- Mr. Fixit: He is of great help to repair and maintain the Odysseus and always carries tools on him.
- Nervous Wreck: He very rarely cools down.
- Nice Guy: As noble at heart, kind and ready to help as everyone else on the Odysseus.
- Parrot Pet Position: He climbs on the shoulder of either Ulysses or Telemachus at times.
- Plucky Comic Relief: He's basically there to provide humor with his clumsiness to counterbalance the otherwise deadly serious tone of the cosmic threat the gods put upon Ulysses, although he's really helpful as well most of the time.
- Ridiculously Human Robots: Nono's antics make him ridiculously human. He packs a wide range of human emotions like shyness, nervosity, anger, sadness and love.
- Robot Buddy: A small robot Ulysses offered to Telemachus for his birthday.
- Small, Annoying Creature: His antics can be pretty annoying at times, although he's nowhere near The Load.
- Trademark Favorite Food: He loves snacking on nails.
A Zotrian teenager and older brother of Yumi. He is saved by Ulysses from being sacrificed to the Cyclops. The gods curse him with suspended animation along with the rest of Ulysses' crew for most of the series, although he is awakened on three occasions before the finale.
Named "Noumaïos" in the French version.
- Animal Eyes: Zotrians have cat-like slanted eyes with a vertical slit for a pupil.
- Bishōnen: A blue-skinned version.
- Brainwashed and Crazy: Numinor is among the companions who get revived and mind controlled to turn against Ulysses and the children in "Mutiny on Board". Yumi manages to free him from the gods' control with her Psychic Link abilities, but only temporarily, as the effort is exhausting for her.
- Pointy Ears: He has pointy ears, like all Zotrians.
- Rapid Aging: What happens to him when the Odysseus is stuck in the realm of Chronos.
Shyrka is the command computer/artificial intelligence of the Odysseus. It speaks with a deep female voice.
- Artificial Intelligence: A super-computer with an intelligence of its own.
- Benevolent A.I.: Always calculates the best options for Ulysses when the Odysseus is in trouble and informs him, Telemachus and Yumi on the ship's state.
- Computer Voice: Shyrka is a computer speaking with the voice of a woman.
- Laser-Guided Amnesia: When sending the Odysseus into the unknown of the Olympus galaxy, the gods wipe the map of return to Earth from Shyrka's memory.
- Master Computer: The Odysseus is nigh-entirely automated, and Shyrka's main job is to control it, make calculations and assist Ulysses when he has to pilot it manually.
The crew of the Odysseus before Ulysses was condemned to wander in the Olympus. The gods placed them in suspended animation for the entirety of Ulysses' ordeal to complicate the task.
- Brainwashed and Crazy: In the episode "Mutiny on Board", the gods revive the companions and Numinor and mind-control them to take over the Odysseus, kill Ulysses and the children and crash the ship into space reef.
- The Cavalry Arrives Late: In the first episode, they decide to come to Ulysses' help when he's cornered by the Cyclops' Monks. When they arrive, the Cyclops has already been killed and the monks are blinded.
- Fate Worse than Death: They are in constant suspended animation and coma and can't do anything, made even worse when the Odysseus is directly threatened.
- Ghostly Glide:
- Whenever they are displaced from the room in which they remain in suspended animation, the curse of the gods makes them come back at it in levitation this way, usually at the end of the episode.
- When the Odysseus reaches the Kingdom of Hades, they are taken out of the ship this way to become literal ghosts.
- Rapid Aging: What happens to them when the Odysseus is stuck in the realm of Chronos.
- Revenge by Proxy: They did not kill the Cyclops by themselves per se (Ulysses and Nono did) but the gods curse them to be inanimate anyway.