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!
United States Secret Service
The Secret Service's special agent in charge of the Presidential Protection Detail who was tasked with protecting many Presidents throughout his tenure.
Prior to and during Day 1, he was a bodyguard for Senator David Palmer during his Presidential campaign. Pierce continued to be detailed with Palmer, who was President through Days 2 and 3, and remained loyal to Palmer even after he was unseated by Vice President Jim Prescott. During Day 4, Pierce was again in the bodyguard detail in Washington, D.C., and helped identify the assassin Mandy for President Charles Logan and his new advisor, former President Palmer. Eighteen months later, Aaron saved First Lady Martha Logan, Russian President Yuri Suvarov, and Anya Suvarov from a terrorist motorcade ambush. He was also instrumental in unraveling President Logan's international criminal conspiracy that day.
By Day 6, Pierce was regularly spending time with Martha, but by Day 7, he was no longer with her and was residing in Washington, D.C. He was called upon by Bill Buchanan to inform Olivia Taylor of the attack on her father, at which point he stayed to look after her at her request. He was, however, influential in bringing her to justice for the murder of Jonas Hodges.
- Ascended Extra: Initially only another supporting Secret Service agent with a few lines, he's become the only character besides Jack to appear in every season (besides season 8).
- Bald of Awesome: He's bald, and one of the most popular characters on the show.
- Bodyguard Crush: On Martha Logan, which is ultimately reciprocated.
- Cool Old Guy
- First Name Ultimatum: He ends his "The Reason You Suck" Speech to Charles Logan by calling him "Charles," rather than "Mr. President" or "Sir".
- Honor Before Reason: Aaron has great respect and loyalty for the office of President, and takes his job very seriously. He does his job, but keeps his moral compass pointing true north at all times.
- Only Sane Man: Within just about any situation, Aaron usually knows exactly what to do.
- "The Reason You Suck" Speech: Delivers one to Charles Logan when he tries to get him to go along with his plans.Aaron: There is nothing that you have said or done that is acceptable to me in the least. You are a traitor to your country and a disgrace to your office. And it's my duty to see that you are brought to justice for what you have done. Is there anything else, Charles?
- Rescue Romance: Things between he and Martha heated up after he saved her.
- Servile Snarker: Particularly to the inept (and ultimately evil) Charles Logan.
- Undying Loyalty: To David Palmer.
- You Called Me "X"; It Must Be Serious: Calling President Logan "Charles" at the end of his "Reason You Suck" Speech. Now knowing how much of a lowlife he is, he refuses to acknowledge the man as President anymore. It's enough to get even Logan to flinch.
A Secret Service agent assigned to protect first gentleman Henry Taylor. He was aligned with Dubaku, as was Edward Vossler.
- Bodyguard Betrayal: To the entire Taylor family. He kills Roger Taylor and tries to kill Henry.
- Character Death: Gedge is killed by Henry.
- Karmic Death: He's killed by the father of the man he murdered in cold blood.
- The Mole: For Dubaku and Hodges.
- The Sociopath: He's so remorseless and emotionless, he certainly comes across as this.
- The Stoic: Rarely if ever shows emotion.
A Secret Service bodyguard and driver of Roger Taylor. Vossler was also a mole for corporate mastermind Jonas Hodges, executive of Starkwood, and part of the massive conspiracy set up within the Taylor administration supporting Sangalan war criminals Benjamin Juma and Iké Dubaku. Vossler had a wife, Carol, and an 11-month old son, Conner.
Like Gedge, he is The Mole working for Starkwood and the Juma regime. He kidnapped Henry Taylor for Dubaku.
- Bodyguard Betrayal
- Character Death: Killed in self-defense by Jack Bauer.
- Even Evil Has Loved Ones: Why he submitted to Jack.
- I Have Your Wife and Son: In what is normally an antagonist's move, Jack, knowing that it'd be unlikely for him to break Vossler through torture in the time frame he had, used a hesitant Reneee to hold Vossler's family hostage to extract his compliance. It worked.
- The Mole: For Hodges and Dubaku.
A Secret Service agent ordered to kill Jack.
- Bald of Evil
- The Brute
- Just Following Orders
- Karma Houdini: Due to it being an executive order, he never gets any comeuppance for trying to kill Jack.
- Post-Final Boss: He's the final physical threat faced in Day 4, but the title of Final Boss ultimately goes to Marwan.
- Psycho for Hire: Despite being a Secret Service agent, he comes across as this. Spalding seems excessively excited at being ordered to kill Jack.
Member of Homeland Security who eventually takes over command of CTU alongside Miles Papazian after the nerve gas attacks in Day 5. Eventually serves as the National Security Adviser to President Wayne Palmer during Day 6.
- Horrible Judge of Character: Has worked with Miles long enough that she believes he can ultimately be brought into the loop to take down Charles Logan. Big mistake.
- Jerk with a Heart of Gold: Karen is argumentative and irritable, but she does ultimately do the right thing and has a strong sense of duty.
- Reasonable Authority Figure: She gradually evolves into this over the course of Day 5.
- Screw the Rules, I'm Doing What's Right!: Sacrifices her career to save Jack's nephew.
- They Do: With Bill Buchanan, despite a very rocky start.
- What Happened to the Mouse?: She isn't mentioned at all post Day 6, which is rather odd considering that her husband dies saving the White House from a terrorist attack.
The Secretary of Homeland Security for the Taylor Administration.
Member of Homeland Security who eventually takes over command of CTU alongside Karen Hayes after the nerve gas attacks in Day 5.
- The Bad Guy Wins: The recording that Jack spent a quarter of a season trying to recover is destroyed thanks to this guy, and Jack actually stopped himself from beating the crap out of him. On the bright, Karen did slap him around a bit.
- It's All About Me/Only in It for the Money
- Jerk with a Heart of Jerk: Miles is a smug asshole who looks down his nose at everyone else while walking around giving off the impression he loves the smell of his own farts. Then it seems like he might redeem himself by helping Jack and Karen...and subsequently betrays them both.
- Karma Houdini: Possibly. On the one hand, we never see him get any comeuppance for his actions on-screen. On the other hand, with Charles Logan no longer around to protect him from any fall-out, chances are that at the very least Hal Gardner kicked him out of the cushy White House job that Logan gave him, to say nothing of any potential charges of aiding and abetting a traitor...
- Smug Snake: Yet in spite of this we never get to see him get his ultimate comeuppance.
The head of the NSA. Stanton appears after Eric Rayburn is fired. Stanton and Peter Kingsley conspired to allow the nuclear weapon into the country, planning for the paramilitary group Coral Snake to neutralize the threat at the last minute; the plot is intended to "strengthen the presidency".
- Artistic License Military: In real life, the director of the NSA is always a four star general or admiral, but Stanton appears to be a civilian.
- Cold-Blooded Torture: He's put through it by the Secret Service. It works, but comes back to bite President Palmer in the ass when some of his Cabinet see it's use as a sign of mental instability.
- The Man Behind the Man: To the Coral Snake Unit.
- Manipulative Bastard: He manipulated entire US agencies to achieve his ends.
- The Mole: For Peter Kingsley, allowing Second Wave to smuggle their nuclear bomb into the United States.
- Well-Intentioned Extremist: Stanton is perfectly happy to let innocent people die to 'strengthen' the country through dangerous means.
- Ambiguously Evil: It's unclear if he was involved with the Kinglsey conspiracy to let the bomb reach U.S. soil or if he's just an asshole.
- Jerkass: He lets CTU get bombed by terrorists while doing everything he can to prevent Lynn Kresge from warning them beforehand.
- Knight In Sour Armor: Assuming he's a good guy, he's this. While he does somewhat try and help find the bomb, he out and out admits he's doesn't think they can find it in time and thinks war is inevitable with those responsible.
- Laser-Guided Karma: The second David Palmer learns he intentionally withheld information about CTU's bomb threat until it was too late to do anything about it, he subsequently gets fired.
- Warhawk: He's more focused on getting President Palmer into a meeting with the Joint Chiefs to plan retaliatory strikes then he is on finding the nuke before it goes off.
A 'floating' NSA agent who helped plan the (supposed) assassination of Victor Drazen.
- Bald of Awesome: He's bald, and due to his general Retired Badass vibe he's very awesome.
- Character Death: A Drazen hitman garrottes him in a public bathroom.
Other Government Officials
A Senator who, during Day 7, conducted an investigation of human rights violations committed by the disbanded Counter Terrorist Unit in Washington, D.C.
- Character Death: Meyer is shot and killed by Starkwood assassin John Quinn.
- Hero Antagonist: To Jack; he's investigating Jack for human rights violations. Considering Jack did violate human rights, Meyer is completely justified in his pursuit. Jack comes to realize this and respects Meyer for it.
- Jerk with a Heart of Gold: Meyer initially comes across as a smug, short-tempered Obstructive Bureaucrat who wants to see Jack go down and he's unnecessarily insulting toward Jack during the investigation. It's gradually revealed that Meyer actually an honest and honorable man. His seemingly overzealous investigation of Jack is simply due to his desire to ensure that nobody is above the law, not even federal agents. Jack ultimately agrees completely with Meyer, and the two becomes allies who respect each other. Meyer was also investigating Starkwood with the objective of taking them down.
- Obstructive Bureaucrat: At first, but really he's a:
- Reasonable Authority Figure: Under dire circumstances, he recognizes that Jack needs his help and he gives it.
- Redemption Equals Death: Well, not really "redemption" due to his status as a Hero Antagonist, but he agrees to help Jack only to be killed immediately—and given the rather obvious motive Jack would have, it's pretty easy to frame him for Mayer's death.
Senator Mayer's Chief of Staff and The Mole for Benjamin Juma.
- Asshole Victim: Given his involvement in aiding Juma and Dubaku, it's hard to mourn him after he dies.
- Character Death: Killed by assassin Quinn in his hospital bed.
- He Knows Too Much: The reason Juma orders his death.
- The Mole: For Benjamin Juma.
- Sickbed Slaying: How Quinn murders him.
- You Have Outlived Your Usefulness: Part of the reason for his death.
A State Department official given the task of serving a Federal subpoena to Jack Bauer. He plays a major part in the evacuation of the Sangalan capital.
- I Gave My Word: He ultimately follows through on his deal with Jack, despite being a very suspicious fellow in general.
- Jerkass: Tramell is snide and condescending.
- Obstructive Bureaucrat: Refuses to save the lives of children unless ordered to or it helps him complete his job.
- You Said You Would Let Them Go: Subverted. For a second it looks he's going to screw Jack over regarding their deal (that Jack returns to the US to stand trial in return for evacuating the children that Jack and Benton were protecting from Juma), but he ultimately proves himself to be a man of his word.