The main protagonist of the series, he's a nerdy tech guru with a fascination with technology. While Jobs remains indirectly touched by the events around him, remaining a perfectly normal human throughout the series, his morals and hope make him a pillar of support to the others.
The Artifact: His name "Jobs" was taken for Steve Jobs, and occasionally other characters lampshade it's a comparatively obscure name to pick compared to, say, "Gates". The series was written in the early 2000s; fast forward as little as three years after the series concluded and Steve Jobs is a household name.
Audience Surrogate: He's the first viewpoint character and retains the POV for most of the first book. Also, he has a much milder personality, not to mention being saner, than most of the other prominent teenagers except perhaps Violet.
Teen Genius: Jobs is just a teenager, but is far more intelligent in technological matters than some adults.
White Male Lead: Despite the extremely diverse cast, Jobs fits the bill perfectly.
Birth Name: Romeo Gonzalez
Jobs's best friend and an adrenaline junkie sports enthusiast, he's had several steel plates and prosthetics implanted in his body after numerous accidents. His enthusiasm and laid-back attitude get whittled down to resolve and determination as the series progresses.
Awesome McCoolname: He's not sure if it's short for "More Steel" or "Man of Steel". His real name, Romeo Gonzalez, is pretty cool too.
Berserk Button: Don't threaten his mom. Rattler learns this the hard way.
Badass Normal: He's one of the few main characters that doesn't get a superpower, but he can still kick ass.
Once a beautiful young girl, Essence Hwang was caught in a house fire and half her face was disfigured. Refusing to hide who she is, she took the name 2Face and took strength from the disgust and revulsion she invoked in people, becoming a stronger but darker figure even before the series began. As it progresses, she starts sliding down the slope from cold but sympathetic protagonist to a manipulative and paranoid antagonist.
Broken Bird: We don't hear much about what she was like before the fire but it's suggested that the experience hardened her considerably.
Dark Action Girl: He's one of the most action-oriented females, but is very dark and shifty.
The Eeyore: She is eternally moody and cynical. It's when she's not that it's time to be worried.
Eyes Are Unbreakable: She can see just fine out of the eye on the scarred side. It's possible that that eye did get blinded and it was repaired or replaced in the other reconstructive surgeries she had after the fire, though.
Fallen Princess: She used to be pretty and popular. After the fire that burned off half her face, not so much.
Gray Eyes: Type 2 — cold, determined, and socially isolated.
I Am Not Pretty: After her disfigurement, she embraced it and dislikes being seen as pretty.
Manipulative Bitch: She goes into it sometimes, most notably in Them when she tricks Yago into thinking it's a better idea to feed Wylson to Tamara's baby than it is to feed her to it. Thankfully, Mother pulls the plug on the illusion that caused the Riders to attack the Remnants before Yago could go through with it.
Mutual Kill: She tries to kill Billy, so he's forced to kill her. And then it turns out that she weakened Billy so much that the Mother easily finished him off.
Nerves of Steel: Nothing shakes her or makes her nervous, and if it does she'll come back shortly.
The Rival: To Yago. With all the other power struggles and gambits being played, the series largely boils down to 2Face versus Yago for control of the remnants. Yago wins, though it's a Pyrrhic Victory.
Sanity Slippage: As the series continues, she becomes more manipulative and cunning. When the remnants are stranded on Earth she falls completely off the deep end into complete paranoia.
A beautiful young girl known as a "Jane", a cultural fad that aspires to the mannerisms of Jane Austim novels, Violet is seen as delicate, weak and girly by the other characters, but has a strong willpower and sense of morals. Her knowledge of art and literature proves useful when the alien machination controlling the ship uses such things to construct a world for them.
Lady of War: She's graceful and beautiful, but can handle herself in a fight just the same.
Last Name Basis: She originally chose to be known as Miss Blake, with Violet as a fallback nickname. Most of the time she's just called Violet, or Violet Blake.
Miss Exposition: She knows all about art. This is helpful when you're in a world made from paintings.
The Ojou: Several of the characters are from rich families, since getting one of the eighty berths on the Mayflower was a matter of having the right connections or enough money to get the right connections. Violet acts the part, though.
Our Vampires Are Different: Her abilities are related enough to this, given that the worms are pretty much indestructible. They can heal her injuries, revive the dead, and doing so passes her powers on to others.
Real Women Don't Wear Dresses: She feels as if this attitude is forced upon modern women; in Nowhere Land, when Wylson complains about the impracticality of Violet's dress, she mutters that she understands Wylson wants her to "dress like a man".
Silk Hiding Steel: She's well-dressed, well-groomed, and polite, but she is not weak.
Straw Misogynist/Female Misogynist: Zigzagged; she's fine with women playing a different role in society than men, but she's not okay with being useless in any situation. She's not misogynistic, exactly, she just has old-fashioned standards.
The Worm That Walks: Eventually revealed as her superpower: her body contains a mass of writhing worms she can control to an extent.
Birth Name: Ruslan, named "William Weir III" by his adoptive parents
One of the most enigmatic characters of the series, Billy was a social outcast on earth and his family just happened to be sent up with the rest. However, uniquely, Billy's life support technology failed, sustaining his life but not his consciousness. Awake and aware for centuries, Billy developed psychic powers, which he may have even had before but were enhanced by the trip. Initially catatonic for the first several books due to being mentally out of sync with time, upon his awakening he takes control of the ship, but in doing so becomes a target for the power-hungry remnants to manipulate.
And I Must Scream: Billy's consciousness doesn't shut down when he sleeps (for some reason), and that extends to the "sleep" induced by suspended animation. So he spent five hundred years immobile, alone, deprived of all sensory input. This eventually slowed down his sense of time so much that he was catatonic for a while after the survivors woke up.
Blessed with Suck: His psychic powers are critical to helping the others, but are hell for Billy personally.
Go Mad from the Isolation: While stuck in And I Must Scream for five hundred years, he went mad after less than a year. Then eventually back to sane. Then mad again, and continued to flip-flop until "the definition of madness became irrelevant." Eventually his brain went so nuts, that he started reading people's minds just to have something to do.
Insanity Immunity: His And I Must Scream situation drives him over the edge of madness, pulls him back over, then thrusts him over again, likely several times. The result is that his mind is so warped, interfacing with Mother and taking control of her has no effect on him, while everyone else is driven nuts.
Mutual Kill: This is how he dies, although it wasn't entirely intentional on both parts. 2Face tries to kill him, so he's forced to kill her. But she weakened him so much that when he faced Mother, it was easy for her to finish him off.
The son of the female African-American President of the United States, Yago is arrogant, ambitious, charismatic and cruel, believing his status on Earth dictates him to lead the remnants. After interfacing with the ship's AI "Mother", Yago becomes a delusional messiah, and he takes control of an outsider faction of the Blue Meanies that he manages to sway to this belief.
A God Am I: Gains this outlook after he interfaces with Mother. Had shades beforehand too.
Alas, Poor Villain: No matter how much you hate him, you have to feel sorry for him when he gets eaten by Tate.
Ambiguously Brown: He's actually mixed-race, with a white father and a mother who's the first African-American president of the United States (the series was written in 2001), but his skin tone is perfect for this trope. Its so perfectly bronze that Violet wonders if it's natural (Yago is known for having had plastic surgery).
Big Bad Wannabe: Yago thinks he's a controlling force of the remnants, but has no real power. When he finally does pull off a scheme successfully, it's only with help from allies, who promptly show him who's really in charge in their partnership.
Narcissist: As far as Yago is concerned, he's the most handsome, intelligent, powerful remnant and thus destined to command them.
Obfuscating Stupidity: He really does become a delusional messiah following his interfacing with Mother, but he plays it up around the others to make them think he's gone completely insane when he's still as manipulative and cunning as before.
Pride: He's practically the embodiment of pride. In his dream world made from his own mind by Mother, the Presidential Seal has his face on it.
Royal Brat: He's the son of the US President. He mentions this quite often.
The AI controlling the massive ship the Remnants are captured by, she was set adrift in space for countless eons. With nothing to do with herself because of a lack of input data, she eagerly plucked the remnants' shuttle from space and crafted parts of the ship after art pieces enclosed on the shuttle in an attempt to make a world for them. She eventually merges with Billy, granting him control of the ship.
Apparently the infant baby of Tamara Hoyle, born during flight and the size of a toddler when they revive her. It soon becomes apparent the baby is much more than just a human though, and is revealed to be a Shipwright, one of the builders of Mother using Tamara to fight for it and absorbing power to grow so it can act on its own.