| Rob Lowe | Sam Seaborn |
| Stockard Channing | Abbey Bartlet |
| Dulé Hill | Charlie Young |
| Allison Janney | C.J. Cregg |
| Janel Moloney | Donna Moss |
| Richard Schiff | Toby Ziegler |
| John Spencer | Leo McGarry |
| Bradley Whitford | Josh Lyman |
| Martin Sheen | President Josiah Bartlet |
| Mary-Louise Parker | Amy Gardner |
| Anna Deavere Smith | Nancy McNally |
| Christian Clemenson | Evan Woodkirk, Smithsonian Curator |
| Dinah Lenney | Mary Klein, Smithsonian Curator |
| Ty Burrell | Tom Starks |
| Bradley White | James |
| Bruce Kirby | Barney Lang |
| Sid Conrad | Ed Ramsey |
| Bill Erwin | Ronald Cruikshank |
| Kim Webster | Ginger |
| Melissa Fitzgerald | Carol Fitzpatrick |
| Peter James Smith | Ed |
| William Duffy | Larry |
| Fort Atkinson | Grant |
| Michael Canavan | Flynn |
| James Hornbeck | Dr. Bedrosian |
| Stan Sellers | Dr. Califf |
| Randy Brooks | Arthur Leeds
(as Randolph Brooks) |
| Kris Murphy | Katie Witt |
| Timothy Davis-Reed | Mark O'Donnell |
| Elizabeth Liang | Staffer |
| Larry Cox | Aide |
| Dean White | Aide |
| Kim Sykes | WLC Secretary |
| Sean Allen Jones | Uniformed Secret Service Agent
(uncredited) |
| Aaron Michael Lacey | Government Employee
(uncredited) |