| Allison Janney as | C.J. (Claudia Jean) Cregg | Chief of Staff |
| Joshua Malina as | Will (William) Bailey | Communications Director |
| Mary McCormack as | Kate (Katherine) Harper | Deputy National Security Advisor |
| Janel Moloney as | Donna (Donnatella) Moss | Santos / McGarry Campaign Staffer |
| Richard Schiff as | Toby (Tobias Zachary) Ziegler | Former Communications Director |
| John Spencer as | Leo Thomas McGarry | Democratic Candidate for Vice President |
| Bradley Whitford as | Josh (Joshua) Lyman | Santos Campaign Manager |
| with Jimmy Smits as |
Matthew Vincente Santos | Democratic Candidate for President |
| Special Guest Stars | ||
| Janeane Garofalo as | Louise "Lou" Thornton | Santos / McGarry Director of Communications |
| Teri Polo as | Helen Santos | Matt Santos' Wife |
| Guest Starring | ||
| Nina Siemaszko as | Ellie (Eleanor Emily) Bartlet | Bartlets' middle daughter |
| Ben Weber as | Vic Faison | Ellie's Fiancée |
| Cress Williams as | Lester | Santos / McGarry Campaign Staffer |
| Ron Canada as | Theodore "Ted" Barrow | Under Secretary of State |
| NiCole Robinson as | Margaret Hooper | Assistant to Chief of Staff |
| Matthew Del Negro as | Bram (Howard) | Santos / McGarry Campaign Staffer |
| Karis Campbell as | Ronna (Beckman) | Santos' Aide |
| Diana-Maria Riva as | Edie (Edith) Ortega | Deputy Campaign Manager for Strategic Planning |
| Shelley Robertson as | Brenda Burke | Ronnie Burke's Mother |
| Lou Beatty, Jr. as | Wilson Burke | Brenda Burke's Uncle |
| Co-Starring | ||
| John Littlefield as | Agent | |
| Duane Shepard, Sr. as | Pastor |
Spencer appeared in seven of the 14 episodes that have been filmed, nine of which have been broadcast.
"How series deal with death"
by William Keck
December 18, 2005
USA Today