Main cast

On 24, main cast is a casting designation for actors who are contracted to appear in any episode of the season at the request of the producers. Main cast actors, despite being first-billed, rarely appear in all the episodes of a given season. Some appear in relatively few episodes (for example, Regina King appeared in only nine episodes).

Season 4 is the only season of 24 in which all of the main characters share scenes together.

The second actor credited in the opening of all episodes is always a woman. It is Leslie Hope in Season 1; Sarah Wynter in Season 2; Elisha Cuthbert in season 3; Kim Raver in Season 4; Kim Raver in 23 episodes of Season 5 and Mary Lynn Rajskub in the one episode of this season where Kim Raver did not appear; Mary Lynn Rajskub in Season 6; either Mary Lynn Rajskub or Cherry Jones in Season 7; Mary Lynn Rajskub in Season 8; and Yvonne Strahovski in Live Another Day.

Season 1

Main article: Season 1

1. Kiefer Sutherland as Jack Bauer
2. Leslie Hope as Teri Bauer
3. Sarah Clarke as Nina Myers
4. Elisha Cuthbert as Kim Bauer
5. and Dennis Haysbert as Senator David Palmer

Season 2

Main article: Season 2

1. Kiefer Sutherland as Jack Bauer
2. Sarah Wynter as Kate Warner
3. Elisha Cuthbert as Kim Bauer (22 episodes)
4. Xander Berkeley as George Mason (15 episodes)
5. Penny Johnson Jerald as Sherry Palmer (13 episodes)
6. Carlos Bernard as Tony Almeida
7. and Dennis Haysbert as President David Palmer

Season 3

Main article: Season 3

1. Kiefer Sutherland as Jack Bauer
2. Elisha Cuthbert as Kim Bauer
3. Carlos Bernard as Tony Almeida
4. Reiko Aylesworth as Michelle Dessler
5. James Badge Dale as Chase Edmunds
6. and Dennis Haysbert as President David Palmer

Season 4

Main article: Season 4

1. Kiefer Sutherland as Jack Bauer
2. Kim Raver as Audrey Raines
3. Alberta Watson as Erin Driscoll (12 episodes)
4. Lana Parrilla as Sarah Gavin (6 episodes)*
5. Roger Cross as Curtis Manning (9 episodes)**
6. and William Devane as Secretary of Defense James Heller (15 episodes)

* — 12 episodes total; added to main cast in "1:00pm-2:00pm"
** — 22 episodes total; added to main cast in "8:00pm-9:00pm"

Season 5

Main article: Season 5

1. Kiefer Sutherland as Jack Bauer
2. Kim Raver as Audrey Raines (23 episodes)
3. Mary Lynn Rajskub as Chloe O'Brian
4. Carlos Bernard as Tony Almeida (6 episodes)
5. Gregory Itzin as President Charles Logan (23 episodes)
6. James Morrison as Bill Buchanan (23 episodes)
7. Roger Cross as Curtis Manning (19 episodes)
8. Louis Lombardi as Edgar Stiles (13 episodes)
9. and Jean Smart as First Lady Martha Logan (23 episodes)

Season 6

Main article: Season 6

1. Kiefer Sutherland as Jack Bauer
2. Mary Lynn Rajskub as Chloe O'Brian
3. DB Woodside as President Wayne Palmer (17 episodes)
4. James Morrison as Bill Buchanan (21 episodes)
5. Peter MacNicol as Tom Lennox
6. Jayne Atkinson as Karen Hayes (18 episodes)
7. Carlo Rota as Morris O'Brian
8. Eric Balfour as Milo Pressman (19 episodes)
9. Marisol Nichols as Nadia Yassir
10. and Regina King as Sandra Palmer (9 episodes)

Redemption

Main article: 24: Redemption

1. Kiefer Sutherland as Jack Bauer
2. Cherry Jones as President-Elect Allison Taylor
3. Bob Gunton as Ethan Kanin
4. Colm Feore as Henry Taylor

Season 7

Main article: Season 7

1. Kiefer Sutherland as Jack Bauer
2. Mary Lynn Rajskub as Chloe O'Brian (13 episodes)
3. Cherry Jones as President Allison Taylor (23 episodes)
4. James Morrison as Bill Buchanan (10 episodes)
5. Annie Wersching as Renee Walker
6. Colm Feore as First Gentleman Henry Taylor (12 episodes)
7. Bob Gunton as Ethan Kanin (18 episodes)
8. Jeffrey Nordling as Larry Moss (19 episodes)
9. Rhys Coiro as Sean Hillinger (10 episodes)
10. with Janeane Garofalo as Janis Gold (21 episodes)
11. and Carlos Bernard as Tony Almeida (20 episodes)

Season 8

Main article: Season 8

1. Kiefer Sutherland as Jack Bauer
2. Mary Lynn Rajskub as Chloe O'Brian
3. Anil Kapoor as President Omar Hassan (15 episodes)
4. Annie Wersching as Renee Walker (13 episodes)
5. Mykelti Williamson as Brian Hastings (17 episodes)
6. Katee Sackhoff as Dana Walsh (20 episodes)
7. Chris Diamantopoulos as Rob Weiss (12 episodes)
8. John Boyd as Arlo Glass
9. with Freddie Prinze Jr. as Cole Ortiz
10. and Cherry Jones as President Allison Taylor (20 episodes)

Live Another Day

Main article: 24: Live Another Day

1. Kiefer Sutherland as Jack Bauer
2. Yvonne Strahovski as Kate Morgan
3. Tate Donovan as Mark Boudreau
4. Mary Lynn Rajskub as Chloe O'Brian
5. William Devane as President James Heller
6. Gbenga Akinnagbe as Erik Ritter
7. Giles Matthey as Jordan Reed
8. Michael Wincott as Adrian Cross
9. with Benjamin Bratt as Steve Navarro
10. and Kim Raver as Audrey Boudreau

Background information and notes

• Season 1 has the smallest main cast, with five people, while Season 7 has the largest main cast, with eleven people.
• Seasons 1 and 3 are the only seasons in each main cast member appear in all 24 episodes.
• Seasons 3 and 4 are the only seasons where no main cast members are killed.
• Season 4 is the only season in which guest stars are upgraded to main cast status partway through. After making six guest appearances, Lana Parrilla was upgraded in episode seven but exited the show in episode 13. After making 13 guest appearances, Roger Cross was upgraded in episode 14 (to "replace" Lana) and remained in the main cast through Season 5.
• Season 4 is the only season to not have an official cast photo of the main cast and omit main cast members from individual promotional photos, as only Kiefer Sutherland and Kim Raver receive them. Ironically, special guest stars Carlos Bernard and Reiko Aylesworth are featured.
• 24: The Official Companion: Seasons 1 & 2 lists Penny Johnson Jerald and Carlos Bernard under the heading "Regular Cast" alongside the main cast for Season 1.
• 24: The Official Companion: Seasons 3 & 4 lists Mary Lynn Rajskub under the heading "Regular Cast" alongside the main cast for Season 4.
• Jeffrey Nordling, Rhys Coiro (for Season 7) and John Boyd (for Season 8) were conspicuously digitally removed from the full cast photos featured on the backs of the DVD and Blu-ray cases. The three are the last billed regulars in credits order in their respective seasons (with the exception of the special "with" and "and" credited actors).
• Beginning with Season 5, the backs of the DVD and Blu-ray cases list the members of the main cast, but only Season 5 has the correct information regarding the regulars. Season 6 lists Roger Cross as a member of the main cast but does not list Carlo Rota, Eric Balfour, or Marisol Nichols; Season 7 lists Jon Voight as a main cast member but does not list James Morrison, Colm Feore, Bob Gunton, Jeffrey Nordling, or Rhys Coiro; and Season 8 does not list Chris Diamantopoulos or John Boyd. Like the above note, the uncredited cast members are the last ones billed excluding the "with" and "and" credits. The sole exception to this is James Morrison, who was billed in between Cherry Jones and Annie Wersching for Season 7 but still was oddly left uncredited.