Aliases: Sarah Reese, Sarah Baum. Mother of John, she was told in the first film that he grows up to be the leader of the resistance against SkyNet. Currently, lives with him, Cameron, and Derek in Los Angeles, trying to stop the creation of SkyNet. Might have or will have cancer - it was what she died of in an alternate timeline.
- Ms. Fanservice: Arguably more to this compared with Linda Hamilton's version, who is closer to real-life Action Girl and understandably less Fanservice.
John Connor (Thomas Dekker)
Aliases: John Reese, John Baum. Sarah's son, the future leader of the resistance. Not quite a leader yet. Currently, neither his mother nor Cameron entirely trust him because he reactivated Cameron after she tried to kill him
- Berserk Button: His mother being in danger.
- Big Good: In the future.
- Broken Ace: Future John is a charismatic leader, a powerful fighter and a masterful strategist but no one knows about the awful things he went through to be what he is or the questionable decisions he made in the past to ensure the victory of the human race.
- Playful Hacker: Mentioned in the pilot, that he's gotten in trouble and blown their cover a few times because of this.
- Pretty Boy: Has long eyelashes, and sometimes his face is practically shiny.
- Science Hero: Since he's destined to fight the Machines, he's naturally highly skilled on the subject of robotics, engineering and computer technology. All the better to kill you with.
- Tired of Running: Repeatedly states this throughout the series. He just wants to prevent the War so it can be over.
- Took a Level in Badass: Season Two was all about this, but it came with knowing what terrifying sacrifices were made for him and by him.
"Thank you for explaining".
Aliases: Cameron Phillips, Cameron Baum, Allison Young. The reprogrammed Terminator (rumored to be TOK715) sent back by future John. The most advanced infiltrating unit seen so far - unlike other Terminators, she can eat food and can cry
. Acts as John Connor's advisor in the future, much to the chagrin of the other resistance fighters.
- Blue and Orange Morality: Cameron's concept of caring, concern, affection, and morality begins and ends with John Connor.
- Came Back Wrong: She survived a car bomb, but was accidentally reset to her Skynet programming. She even told Sarah not to let John bring her back if it happens again.
- Cloud Cuckoolander: Comes off as one even before her chip was damaged.
- A Day in the Limelight: "Allison From Palmdale" (Cameron's origin) and "Self Made Man" (Cameron's night time activities)
- Deconstruction: "Self-Made Man" deconstructed Cameron as a character.
- I Will Protect Her: A gender flipped version where Cameron will do everything to protect John, as well as prepare him for Judgement Day and beyond.
- Magical Girlfriend: Deconstructed. She's an unearthly beautiful girl devoted to John but she also lacks empathy towards anyone else and is willing to protect John by any means at her disposal.
- Manipulative Bitch: Cameron is very good at getting the reaction she wants out of people.
- No Sense of Personal Space: She stands too close to people and stares when she evaluates their threat level.
- Passive-Aggressive Kombat: Punishes conversational partners who don't make her happy with disturbing revelations.
- Pet the Dog: All the time with John, from reassuring him of his value to acting as a semi love interest. Also towards a researcher who helps her, from helping him move about in his wheelchair to letting him fire her gun. Then she lets slip that he's had a relapse of cancer he thought he had finally gotten cured, causing him to possibly be Driven to Suicide.
- Red Eyes, Take Warning: "Born To Run." That's all that needs to be said.
- Unitard Of Power: She wears a dark red unitard when going undercover as a ballet student.
- Waif-Fu: Comes with being played by Summer Glau.
- Weak, but Skilled: At least in relation to other Terminators. She doesn't have their raw strength and often can't beat bigger Terminators in a straight up fight - which is why she fights dirty.
- Yandere: Very loosely, but there are shades of this in some episodes. She'll protect John, no matter the cost.
- You Have Outlived Your Usefulness: In "The Demon Hand" to the Russians, after getting what she needed from them. Note in this case she doesn't actually kill them, but simply ignores them once she has what she needs, allowing them to be killed because their survival was then irrelevant to her overall mission.
- Younger than They Look: Cameron's exact age is never specified, but she's almost certainly younger than her human appearance makes her seem.
Charley Dixon (Dean Winters)
"He was a scary robot but you, you're a really scary robot."
Sarah's former fiance, he's since married someone else until she dies by Cromartie's hands
. Eventually dies protecting John Connor
James Ellison (Richard T. Jones)
"These are more than machine but I will never make the mistake of thinking them human".
An agent of the FBI, he started out trying to stop the Connors...until he started believing them.
- Kill and Replace: Not him, but a Terminator who tried to kill and replace him to steal his identity. It's foiled, however, by Cromartie, of all people... I mean cyborg. See Cromartie section below.
- Shout-Out: His name is a dual reference to James Cameron (Original writer) and Harlan Ellison (Who claims to have written it first).
- Well-Intentioned Extremist: Avoids ever being an outright villain due to the fact that he had good reason to believe Sarah was seriously dangerous. He was just an officer who ended up in really deep stuff.
Derek Reese (Brian Austin Green)
"We can go back. We can fix all the mistakes".
John's uncle from the future, he came back to get a chess playing computer named the Turk and kill its creator, Andy Goode
. Eventually is shot in the head by a Skynet Terminator.
And now alive again in an alternate future timeline
Cromartie (Garret Dillahunt)
"Thank you for your time."
The Terminator sent after John at the same time Cameron was. His chip is eventually destroyed, but his body ends up being used as the "face" of the Turk/John Henry supercomputer.
- Magic Plastic Surgery: Justified in that he's a robot and once he got new flesh put back on his body, he forced a plastic surgeon to make him look like a failed actor (in a procedure that would normally kill a human being).
- The Nth Doctor: Played by Owain Yeoman in the pilot before he gets blown up, Garret Dillahunt in the main seasons after he gets a new flesh covering, and an uncredited stuntman in the interim stages.
- Villainous Rescue: He destroyed a fellow Terminator who tried to Kill and Replace James Ellison, only because his mission is conflicted that he believed James can lead him to the Connors at the time.
The Connors' new and very pregnant neighbor.
Riley Dawson (Leven Rambin)
"I'm a crazy, badass ninja!"
John's new friend at school. Not very well liked by the audience. Actually working with Jessie to manipulate John Connor.
- Broken Bird: The cracks begin to show early that she's had a troubled past, once it's revealed she grew up during the war with the machines, it becomes clear she's been barely holding it together most of the time.
Morris (Luis Chávez)
John's other friend at school. Asked Cameron to the prom. Not seen since the first season.
Dr. Peter Silberman (Bruce Davison)
A psychologist who laughed at the idea of the Terminators. After the events of T2, he retreated to a mountain cabin and became an apocalyptic believer.
- Laser-Guided Karma: At the end of "Demon Hand," he gets locked up in the same mental hospital he used to run, in Sarah's own room.
Catherine Weaver (Shirley Manson)
"The project's name is Babylon. It's from The Bible."
CEO of Ziera Corp. She had the Turk stolen and set a group of people to work with it on "Project Babylon." Also, is a liquid metal T-1001 Terminator.
- Kill and Replace: May or may not be, since it's unclear if the real Catherine Weaver is actually killed in a helicopter crash (that killed her husband) or killed by this T-1001 who assumed her identity.
- Light Is Not Good: She wears a lot of white. Downplayed because she's technically an Anti-Hero, as it is implied that she did consider allying with the resistance to take down Skynet, but turned down the offer in part due to Jessie, and that Project Babylon was also implied to be a means to counteract Skynet.
- Unflinching Walk: After she killed the people at the "air conditioning factory". And then Out of the Inferno as well.
Savannah Weaver (Mackenzie Brooke Smith)
"I want my old mommy back."
Daughter of (the real) Catherine Weaver. She becomes best friends with John Henry.
- Disappeared Dad: We know in one episode her parents are technically dead, but...
John Henry (Garret Dillahunt)
"Why is a math book so sad?"
The AI built and developed from Andy Goode's Turk supercomputer, using Cromartie's body
as a means to communicate with others and manipulate its environment. Extremely
intelligent, but almost childlike.
- A.I. Is a Crapshoot: Averted. Weaver specifically enlisted Ellision to teach John Henry morality and ethics so he develops properly.
- Basement-Dweller: It's not like he has any choice on the matter since his body is permanently hooked up to the computer that's used to run his AI.
- Cain and Abel: John Henry asks which "brother" he is. Weaver's response is he might be neither, and may in fact be God.
Dr. Boyd Sherman (Dorian Harewood)
"Because it has so many problems".
A child therapist whose name was found on the blood-stained basement. Weaver hires him as a consultant to help her understand the strange behavior of her AI.
- Dropped a Bridge on Him: Died of heat stroke after the AI rerouted the power from the air-conditioning to continue powering itself.
- Token Minority: The only other African-American character in the show aside from Ellison.
Jesse Flores (Stephanie Jacobsen)
"Sunset's at 5:47. I'm not gonna miss that sucker."
Resistance fighter who traveled back in time to escape the hell of the future. Has an intimate relationship with Derek Reese. Actually traveled back in time on her own with Riley to try and separate John and Cameron, and is also implied to be an alternate counterpart to Jesse from Derek's timeline.
- Batman Gambit: Get Riley to threaten Cameron enough to kill her so John would be alienated from Cameron in the first place. If that doesn't work, kill Riley yourself, then pin the blame on Cameron. Unfortunately for her John figured it out before he terminated Cameron.
- Bitch in Sheep's Clothing: Revealed herself as this the moment she slapped Riley, and right after Riley admitted to screwing up, was not in good shape and was asking to stay with Jesse for a while.
- A Day in the Limelight: "The Last Voyage of the Jimmy Carter".
- Wham Line: gets one by Derek before we see the last of her. We don't know if he shot her or not.
" You're not my Jesse."
"I live in a tunnel. I eat garbage for dinner"
Resistance fighter in the future. Captured by Skynet, and who Cameron's physical features are based on. Later killed by Cameron for lying to her.
Implied to know John Connor personally. And now, most likely alive again in the alternate future timeline.
- Beauty Is Never Tarnished: Averted; her face is marked by a lot of open cuts and scratches.
- Determinator: She will escape, or die trying. Barring that, she's not gonna do anything to compromise John Connor's safety.
Jodie (Leah Pipes)
"I got this necklace at this awesome thrift store in Echo Park."
A runaway Cameron befriended in "Allison in Palmdale".