BEWARE OF SPOILERS. Due to the nature of the show, with its many Walking Spoiler characters, twists, and turns, the only spoilers whited out are those for the current season "24: Live Another Day". Proceed with caution!
Federal Bureau of Investigation
The Special Agent in Charge of the FBI's Washington Field Office during Day 7. He was reluctant but accepted Renee Walker's proposal to enlist Jack Bauer to help bring down his former ally Tony Almeida who was behind some technology thefts that occurred prior to Day 7. Over the course of the day his attitude towards Bauer changed after he recognized that he judged Jack for the wrong reasons. Almeida gained the trust of the FBI before stealing a lethal bioweapon and killing Larry by suffocating him.
- All Love Is Unrequited: He has some strong feelings for Renee, which are not returned.
- Big Damn Heroes: He personally leads the assault team charged with taking back the White House from Juma's men. Also a case of Screw the Rules, I'm Doing What's Right!, because he hadn't gotten the Vice-President's clearance beforehand, instead realizing it was time to act when he heard an explosion from the White House's interior.
- Character Death: Larry is killed by Tony Almeida.
- Et Tu, Tony?: Tony smothers him after he's incapacitated, much to his (and everyone else's) surprise.
- FBI Agent: Special agent in charge, even.
- Fire-Forged Friends: What he thinks he and Tony have become after going through hell to take down Jonas Hodges. Sadly turned on its head, given how Tony ends up killing him at the end of the very episode in which he expresses this sentiment.
- Good Is Not Nice: Larry is morally upright, but not exactly charming.
- Hero Antagonist: Although he gradually becomes a solid ally for Jack, initially Larry was extremely wary and distrustful of him. After all, to his knowledge Jack was a dangerous and unpredictable man.
- Honor Before Reason: Larry has a strong moral compass that sometimes affects his judgement.
- Inspector Javert: When he thinks Jack was responsible for the deaths of Ryan Burnett and Senator Blaine Meyer.
- Jerk with a Heart of Gold: Larry can seem whiny and judgemental, but he cares deeply about his country and the people who work for him.
- Oh, Crap!: His last words are "Oh God" after Tony shows his true colors.
- Sacrificial Lion: His death demonstrates just how fargone Tony is. It also ends up serving as a catalyst for Renee's descent into Dark Action Girl territory.
- Screw the Rules, I'm Doing What's Right!: What he eventually does.
- Suspiciously Similar Substitute: Plays a role similar to Ryan Chappelle and George Mason in the early years of the show, where his adherence in the rules made him an Obstructive Bureaucrat to Jack. Subverted in that, unlike Chappelle, Larry wasn't so much mindful of covering his ass as he was of trusting Bauer (who, at that time, was being indicted by the US Senate), which makes his antagonism more of a matter of principle.
- Wham Episode: When Tony smothers him to death.
An FBI special agent from the Washington Field Office. She was involved in investigating the technology thefts prior to Day 7 and was an integral agent in bringing down the threats that arose on Day 7. Upon meeting Jack Bauer she was horrified at his willingness to do whatever was necessary to follow a lead. However as the day progressed she began to see the necessity behind Jack's actions and realized that the only way to bring down Alan Wilson, the main conspirator for the events of the day, would be to act as Jack would have done.
After torturing Wilson to near death, Renee was dismissed from the FBI. She was called in to help in CTU New York with regards to her past undercover with the Russian crime syndicate, Red Square, but some felt she was not up to the task. She was shot at Jack's apartment by Pavel Tokarev, a sniper working for Mikhail Novakovich and Yuri Suvarov, and died in the hospital minutes later.
- Action Girl: She shows herself to be an absolute badass during Day 7.
- Dark Action Girl: During Day 8.
- Anti-Hero: Type IV or even V in Day 8.
- Break the Cutie: Day 7 utterly breaks her, whereas she's been a somewhat idealistic, noble agent before.
- Broken Bird: The death of Larry Moss, the numerous traumas she endures and the sheer existence of Alan Wilson completely break Renee.
- Buried Alive: Jack and Tony do this to her during Day 7 to keep David Emerson from getting suspicious so she doesn't end up getting killed by him for real. Bill and Chloe track down where she's buried and dig her up in time later on.
- Character Death: Renee is killed by a sniper (later revealed to have been Pavel Tokarov).
- Kill the Cutie
- Death by Sex: Renee is killed almost immediatly after having sex with Jack.
- Death Seeker: In the first half of Day 8.
- Distaff Counterpart: To Jack, during Day 8.
- Dramatic Irony: She comes into Day 8 broken and uncaring of whether she lives or dies. Eventually, she comes to appreciate life again when she and Jack act on their feelings for each other. However, she dies shortly after the two consummate their relationship.
- Fan Disservice: Her death is preceded by a gratuitous Shower Scene.
- Fan Nickname: "Female Jack" and "Jill Bauer".
- Fiery Redhead: Averted, she's rather calm and collected with a strong moral compass. It's played straight in Day 8, although her hair does get darker.
- No Kill Like Overkill: What she does to Vladimir Laitanan.
- Rape as Backstory: Laitanan had sexually assaulted Renee while she had been undercover.
- Sacrificial Lion: Her death is one half of what triggers Jack's Roaring Rampage of Revenge, the other half being Allison Taylor's betrayal of him when he attempts to avenge Renee while still following the rules.
- She Knows Too Much: Why she was killed: she recognized Pavel as he murdered Samir Mehran so she could likely trace him back to his employers.
- Stuffed into the Fridge: Despite being an immensely popular character praised by critics and audiences, having her a complex character arc while providing balance to Jack and even raising talk of a possible spin-off, Renee is killed off during Day 8 to send Jack on a Roaring Rampage of Revenge.
- Supporting Protagonist
- Unresolved Sexual Tension: With Jack, but subtly; in fact the show took some effort to downplay it during Day 7.
- They Do: On Day 8.
- Played with regarding Larry. While the attraction seems to be coming more from his part, she nevertheless is shattered by his murder, and tortures Alan Wilson nearly to death offscreen out of vengeance. It's also hinted that this is the dominant factor in influencing her Start of Darkness that lasts through the first few episodes of Season 8.
- White Shirt of Death: Well, white Modesty Towel of death, but same effect — blood and all.
- Wide-Eyed Idealist: She was this early on in Day 7.
An FBI agent active during Day 6. He was sent to the Islamic-American Alliance to investigate files, and he later lead a sting operation that placed Walid Al-Rezani undercover with prisoners.
An analyst at the FBI Field Office in Washington, D.C. during Day 7. Her expertise played a crucial role during the government's efforts to foil the various terrorist threats posed during that day.
An analyst at the FBI office in Washington, D.C., during Day 7. His wife's name was Christina. Sean worked for an organization within the government supporting the operations of Iké Dubaku, who was being tracked down by the Bureau. Sean's superior in assisting Dubaku was Ryan Burnett.
- Deadpan Snarker
- Jerkass: Sean is a basic disinterested prick to just about everyone.
- Jerk with a Heart of Jerk: And then he's revealed to be a damn sociopath.
- The Mole: For Dubaku.
- Only in It for the Money: The reason he became The Mole.
- Shoo Out the New Guy: He was never seen again after he was arrested in the 10th episode of season 7, the earliest point in any season a main cast member was written out of the series.
- Smug Snake
- The Sociopath: He cheats on his wife, betrays his co-workers, murders his lover in cold blood and never shows anything even approaching a shred of remorse.
- The Stoic: Rarely shows much emotion, usually looking merely bored.
- Your Cheating Heart: Despite being married, he's been having an affair with fellow analyst Erika.
An FBI analyst during Day 7. She was working with Sean Hillinger and Ryan Burnett as part of the conspiracy assisting Sangalan war criminal Iké Dubaku.
- Horrible Judge of Character: Erika fell in love with The Sociopath Sean Hillinger, and trusts him. Her trust is repaid with a bullet.
- It's All About Me
- The Mole: For Dubaku, along with Sean.
- Love Makes You Evil: She became The Mole apparantly at Sean's behest, who she's in love with.
- Your Cheating Heart: She's in a relationship with Sean Hillinger, despite him being married.
The designer of Homeland Security's Firewall Project. Latham was kidnapped by a group of terrorists led by former CTU agent Tony Almeida. Latham was taken to Almeida's workstation where he was forced to "fix" a device for the terrorists so they could get past the Firewall Project which he designed.
- Butt-Monkey: His very first appearance sees him being abducted by Tony on Dubaku's orders. For the rest of the time we see him he's regularly abused and mistreated by Dubaku, and he's forced to take it all due to his family's lives being threatened, all the way up until he's forced to sacrifice himself so Dubaku can make an escape.
- Character Death: He's blown up by his kidnappers.