Dylan Hunt is a member of the Intergalactic Systems Commonwealth High Guard. Born on the planet Tarn-Vedra, Hunt is human, half genetically enhanced because his mother was a heavy-gravity worlder. Because of this, he is much stronger than the average human.

Dylan was born in Visharna-Tarn, to a father employed as a gardner at the Imperial Gardens and a mother employed as a high-G shuttle pilot.

Dylan served two years as an enlisted man. He then attended the High Guard Academy and graduated with honors. He served in Argosy Special Ops and commanded the Crimson Eclipse.

Immediately prior to his command on the Andromeda, he was given a secret mission to extradite the dictator Ferrin from the planet Mobius so he could stand trial on Tarn-Vedra for war crimes. When he confronted Ferrin he was shot in the side and Ferrin was killed. The mission was still seen as a success by the High Guard and Dylan was given command of the Andromeda and his partner on the mission, Gaheris Rhade, was made his first officer.

Dylan dated Sarah for several years and they were going to get married until Hunt was presumed dead or lost at the Battle of Hephaistos.

At the Battle of Hephaistos, Dylan was betrayed by his first officer and best man, Gaheris Rhade. His crew abandoned ship and he killed Rhade in self defense. The Andromeda was pulled near a black hole and experienced very extreme time dilation. While seconds passed for Dylan and the Andromeda, 303 years passed for the rest of the universe.

Dylan was rescued when the Eureka Maru attempted to salvage the Andromeda. He convinced the crew of the Maru to join him and help him restore the now fallen Systems Commonwealth.

Presently he has helped form a small Commonwealth, with about 50 member worlds.

When he found out his father was a Paradine, he learned to use his powers.

Rebecca "Beka" Valentine is human but has never lived on a planet. The daughter of a small-time cargo runner and occasional smuggler, Beka grew up on a ship roaming space and has spent her entire life searching for the big score and the fat payday.

She is now first officer of the Andromeda Ascendant, as well as commander of her own small cargo ship, the Eureka Maru. She is fiercely loyal to her crew and ship, but follows her own shadowy code. Though she remains deeply skeptical of Dylan's quest to restore the Commonwealth, she takes her duty as his first officer seriously. She'd lay down her life before she'd let him down. As Andromeda's best pilot, she's gotten him out of more than one scrape, and continues to prove herself a valued member of the crew.

When she was trapped in an alternate dimension with Tyr, the Abyss possesed her to spy on Dylan. Later the crew managed to extract the Abyss from her.

In the episode "Pride Before The Fall", Beka had relations with Drago Museveni, posing as a man named Peter. Drago Museveni takes samples of Beka's DNA, then disappears through the Route of Ages. By a strange mix of time travel, Beka became the matriarch of the entire Nietzschean race. Hence, if anyone kills her, all Nietzscheans will cease to ever exist. Including the Andromeda and its crew. Furthermore, Nietzscheans grew up in reverence of Drago Museveni, and would revere Beka as the Alpha Mother.

Tyr Anasazi out of Victoria by Barbarossa is a Nietzschean and the last known surviving member of Kodiak Pride. After his pride was betrayed by its allies, Tyr was captured by slavers and sold to work in diamond mines. One day the mines caved in and he was buried 200 metres underground, but he escaped. He became a mercenary and was secretly hired by a Nightsider, Gerentex to secure the presumably lost High Guard warship Andromeda Ascendant with the crew of the Eureka Maru.

Following this incident, he joined Captain Dylan Hunt in his quest for a restored Commonwealth alongside the Maru's crew: Beka Valentine, Seamus Harper, Trance Gemini and Rev Bem.

Tyr married Freya of Orca Pride and she gave birth to their son, Tamerlane. Tyr was separated from her shortly after the consummation of his marriage and they met again more than a year later. Tamerlane was the genetic reincarnation of the Nietzschean progenitor, Drago Museveni. This attracted the attention of the Genites, a group of genetic purists who sought to destroy genetically enhanced humans. Freya died in the conflict with the Genites and Tamerlane was sent away secretly.

In season 4, he tricks other Nietzschean Prides into thinking he is the reincarnation of Drago Museveni and left the Andromeda because his people were working with the Abyss. He then looked for the Star Map to the Route of Ages and ultimately ended up in an alternate universe with Beka. He bargains with the Abyss: if he is set free, they can use Beka as a spy on Dylan. Once the Abyss sealed its influence inside Beka, Dylan, Rhade and Harper arrived and shot him in the back. His body fell into the abyss (a canyon with endless darkness) thus ending his life.

Seamus Harper is a member of the Andromeda Ascendant crew and is the engineer and fix-it man. Harper is the only member of the Andromeda's crew born and raised on post-Commonwealth Earth. After the Fall, it was conquered by a Nietzschean pride called the Drago-Kazov, who treated unengineered humans poorly, and its inhabitants were frequently attacked by the Magog. The human denizens of Earth lived in poverty and conflict, which prompted Harper to run away.

Harper joined the Andromeda crew in 303 AFC (After the Fall of the Commonwealth) along with Beka Valentine, Trance Gemini, and Rev Bem. He was previously recruited onto the Eureka Maru by Captain Valentine's old boyfriend, Bobby Jensen.

Harper's tumultuous upbringing has left him with somewhat deficient social skills, and he prefers to spend his time in the company of machines, constantly fixing and upgrading Andromeda and her various systems. He is quirky, funny, a bit ego-centric, but undoubtedly a genius. He also constructed the humanoid avatar for the Andromeda, called Rommie by the crew. Harper has a neural interface at the base of his skull, which he uses to jack into computers, sentient ships, and programs.

Trance Gemini’s first appearance on the show is as a young, bubbly, purple-skinned alien of an unknown origin with a prehensile tail. She is somehow representing a cartoony archetype of the animal-like, sweet, sensitive and funny fantasy creature and serves as a comic relief. Her way of thinking is somehow 'out of this world' and innocent. For example, her report on Dylan Hunt's rescue was "I wondered where you are, found you, and brought you back".

She was the last member to join the crew of the Eureka Maru before they rescued the Andromeda Ascendant and its captain, Dylan Hunt, from a black hole. On the Andromeda, she serves as their environmentals and life support officer, xenobiologist, botanist and physician, and is consequently often found in the ship's hydroponics garden or medical deck.

She is mysterious about her true nature, but has made guesswork that saved the crew of the Andromeda on many occasions. This ability has also helped her in gambling games, espionage and thievery when she and the crew needed it.

In mid-season two, Trance undergoes a physical transformation via the effects of a Tesseract machine, which folded space and time. She changes places with a being that tells her that she is an older version of herself. The "new" Trance is still played by Laura Bertram and has the same facial features, but has a golden skin tone instead of purple.

Trance is the avatar of the original Vedran sun which was built to destroy the Abyss and has special powers and abilities. For instance, she can transform herself into a model of her sun and go supernova at will.

She plays a critical role during the Nietzschean Secession, in which the crew of the Andromeda fought with former crewmember Tyr Anasazi to obtain passage to the Route of Ages.

When the crew was in Seefra, Trance was in her sun state known as the core creature. Once she was in her humanoid form, she had no recollection of who she was or what she could. On Seefra-2, she met a man named Ione who was really the missing moon of Tarn Vedra. Later, the Nebula sealed her in her own sun but thanks to Dylan and Rhade, she was rescued.

Unfortunately, she found out that her people were under the spell of the Abyss but she used her sun to destroy it.

Rommie is the humanoid avatar of the Andromeda Ascendant, a starship in the TV series. She was built and given material form as an android by the engineer, Seamus Harper, who also seems to be infatuated with his work.

Rommie has complete power and control over her ship. Along with her android form, she also communicate via her hologram and online virtual. She is very loyal to her crew, especially to her captain, Dylan Hunt. She has abilities that would be considered superpowers by humans, such as moving extremely fast when need be, super strength, resistance to injury and using the sensors in her hands to sense things few ordinary humans could, such as lying and internal injury. Even though she is an android, she has human emotions as can be seen in the season one episode "Star Crossed", in which she falls in love with another ship avatar, Gabriel (played by Lexa Doig's husband Michael Shanks).

The two Rommies interact perfectly but seem to be independent. Since her creation, the android Rommie is shown to have evolved differently from the ship's AI, and both of them (android and hologram) are sometimes found together chatting, even arguing against each other's opinions. Their biggest difference is that the android, as a creation of Harper, is intended to be human-like and sentimental. At the end of Season 4, Rommie blew up. All that was left was her head that was partially damaged and her AI core.

Rev Bem is a Magog and a devout member of the Wayist religion, therefore he has to control his baser instincts to kill other living beings for food. His full Wayist name is Reverend Behemial Far Traveler, shortened to Rev Bem. His original Magog name is Red Plague.

In Season 4, he was possessed by the Abyss and tricked Dylan.

The name 'Bem' likely comes from the acronym for 'Bug Eyed Monster', a nickname for science fiction aliens.

Telemachus Rhade is a Lieutenant Commander of the Systems Commonwealth serving aboard the Andromeda Ascendant under Captain Dylan Hunt. He is also a direct descendant of Gaheris Rhade (also played by Bacic as a recurring role in several episodes, mostly as flashbacks), a former executive officer of the Andromeda who betrayed Captain Hunt and the Commonwealth 300 years prior, contributing heavily to the fall of the Commonwealth. Telemachus is also the genetic reincarnation of his ancestor, which means that he possesses exactly the same DNA sequence as Gaheris- they are genetically identical (and consequently visually identical, naturally, which is why the two men are played by the same actor).

Captain Hunt first encountered Rhade while he was an Admiral of the home defense fleet and the leader of the isolationist movement on Terazed, a planet which had maintained the traditions of the Commonwealth ever since the fall 300 years prior. Terazed eventually joined the Commonwealth and at some later point, Rhade was demoted to Lt. Commander. Rhade joined the crew of the Andromeda after he assisted the crew in tracking down former crew member Tyr Anasazi, who had escaped custody in an attempt to acquire the map to the Route of Ages.

Doyle is a female android and was built by Seamus Harper to protect him, and is similar to the character Rommie.  She holds many of Rommie’s core AI memories inside of her mind and has nightmares about past space battles that the Andromeda was involved in.  She eventually learns of her true nature and grows to accept it.  When she finally gets on board the Andromeda she has a battle of wills with Rommie for control of the ship but it ends in a stalemate when both realise that neither can win and Dylan orders them to cooperate.  Eventually Rommie’s AI is extracted and Doyle can take charge of her life and she chooses to help her friends defeat the Abyss, even though her individual life means a great deal to her.