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 "24: Live Another Day". Proceed with caution!
The Bauer Family
- The Bauer Familynote Jack Bauer, Kim Bauer, Teri Bauer, Phillip Bauer, Graem Bauer, Marilyn Bauer, Josh Bauer
United States Federal Government
- Presidentsnote David Palmer, Jim Prescott, John Keeler, Charles Logan, Hal Gardner, Wayne Palmer, Noah Daniels, Allison Taylor, Mitchell Hayworth, James Heller
- The White Housenote Mike Novick, Walt Cummings, Reed Pollack, Tom Lennox, Ethan Kanin, Olivia Taylor, Rob Weiss, Mark Boudreau, Keith Palmer, Nicole Palmer, Martha Logan, Henry Taylor, Roger Taylor, Audrey Boudreau, Lynne Kresge, David Brucker
- Other Government Groups & Officials
- First Families
Government Agencies
- Counter Terrorist Unitnote George Mason, Ryan Chappelle, Lynn McGill, Richard Walsh, Brad Hammond, Bill Buchanan, Christopher Henderson, Jack Bauer, Alberta Green, Tony Almeida, Erin Driscoll, Michelle Dessler, Nadia Yassir, Nina Myers, Curtis Manning, Ronnie Lobell, Mike Doyle, Chase Edmunds, Gael Ortega, Lee Castle, Tom Baker, Kim Bauer, Edgar Stiles, Morris O'Brian, Milo Pressman, Adam Kaufman, Sarah Gavin, Carrie Turner, Jamey Farrell, Marianne Taylor, Spenser Wolff, Shari Rothenberg, Paula Schaeffer, Brian Hastings, Cole Ortiz, Arlo Glass, Dana Walsh
- Federal Bureau of Investigationnote Larry Moss, Renee Walker, Janis Gold, Sean Hillinger, Erika, Michael Latham
- Central Intelligence Agencynote Steve Navarro, Kate Morgan, Erik Ritter, Jordan Reed, Gavin Leonard, Mariana
- United States Military
Foreign Governments
Terrorist & Criminal Groups
- The Drazen Syndicatenote Victor Drazen, Andre Drazen, Alexis Drazen, Ira Gaines, Kevin Carroll, Rick Allen, Dan Mounts, Eli Stram, Jonathan Matijevich, Ted Cofell
- Second Wavenote Syed Ali, Marie Warner, Joseph Wald, Eddie Grant
- The Peter Kingsley Groupnote Peter Kingsley, Max, Alexander Trepkos, Jonathan Wallace, Ronnie Stark, Raymond O'Hara
- The Salazar Family & Associatesnote Ramon Salazar, Hector Salazar, Claudia Hernandez
- The Saunders Family & Associatesnote Stephen Saunders, Jane Saunders, Marcus Alvers, Michael Amador, Osterlind, Arthur Rabens
- Marwan Terrorist Group & Associates
- Russian Separatist Movementnote Vladimir Bierko, Ivan Erwich, Anton Beresch, Colette Stenger, Jacob Rossler
- Sentox Conspiracynote Charles Logan, Walt Cummings, James Nathanson, Christopher Henderson, Graem Bauer, Conrad Haas
- Fayed Terrorist Cell
- Starkwood Groupnote Jonas Hodges, Doug Knowles, Greg Seaton, John Quinn, Stokes
- Prion Variant Cabal
- Red Square & Associatesnote Sergei Bazhaev, Josef Bazhaev, Oleg Bazhaev, Davros, Vladimir Laitanan, Ziya Dakhilov, Lugo Elson
- Open Cellnote Adrian Cross, Chell, Stosh
- The Al-Harazi Familynote Margot Al-Harazi, Simone Al-Harazi, Ian Al-Harazi, Naveed Shabazz, Farah Shabazz, Yasmin Shabazz, Derrick Yates
Other
- Civilians & Jack's Allies
- Other Antagonistsnote Cheng Zhi, Sherry Palmer, Nina Myers, Kevin Wade, Carl Webb, Mandy, Gary Matheson, Alan Milliken, Marcus, Rouse, Cole, Jason Pillar, Kevin Wade, Nick Coughlin