| Alan Alda | Senator Arnold Vinick |
| Kristin Chenoweth | Annabeth Schott |
| Allison Janney | C.J. Cregg |
| Joshua Malina | Will Bailey
(credit only) |
| Mary McCormack | Kate Harper
(credit only) |
| Janel Moloney | Donna Moss |
| John Spencer | Leo McGarry
(credit only) |
| Bradley Whitford | Josh Lyman |
| Jimmy Smits | Matthew Santos |
| Martin Sheen | President Josiah Bartlet |
| Janeane Garofalo | Louise Thornton |
| Teri Polo | Helen Santos |
| Ron Silver | Bruno Gianelli |
| Patricia Richardson | Sheila Brooks |
| Stephen Root | Bob Mayer |
| John Aylward | Barry Goodwin - Former DNC Chair |
| Melinda McGraw | Jane Braun |
| Matthew Del Negro | Bram Howard |
| Karis Campbell | Ronna |
| NiCole Robinson | Margaret Hooper |
| Renée Estevez | Nancy |
| Diana Maria Riva | Edie Ortega
(as Diana-Maria Riva) |
| Shawn Michael Patrick | Gene - Santos Transition Team |
| Michael Bofshever | Klain |
| Foo Fighters | Themselves |
| Mike Kersey | Bruce |
| Ivan Allen | News Anchor Roger Salier |
| Penny Griego | Anchor #2 |
| Paul Moyer | Anchor #3 |
| Robert Aguilar Jr. | Marine Guard
(uncredited) |
| Dax Garner | Foo Fighters Roadie
(uncredited) (unconfirmed) |
| Fatima Grate | Vinnick Staffer
(uncredited) (unconfirmed) |
| Omar Janakat | Santos Supporter
(uncredited) (unconfirmed) |
| Mike Monroe | Security Guard
(uncredited) |