| Dulé Hill as | Charlie (Charles) Young | Personal Aide to the President |
| Allison Janney as | C.J. (Claudia Jean) Cregg | Press Secretary |
| Joshua Malina as | Will (William) Bailey | Deputy Communications Director |
| Janel Moloney as | Donna (Donnatella) Moss | Assistant to Deputy Chief of Staff |
| Richard Schiff as | Toby (Tobias Zachary) Ziegler | Communications Director |
| John Spencer as | Leo Thomas McGarry | Chief of Staff |
| Bradley Whitford as | Josh (Joshua) Lyman | Deputy Chief of Staff |
| and Martin Sheen as |
Jed (Josiah Edward) Bartlet | President of the United States |
| Special Guest Stars | ||
| Mary-Louise Parker as | Amy (Amelia) Gardner | FLOTUS' Chief of Staff |
| Jesse Bradford as | Ryan Pierce | Intern |
| Gary Cole as | Robert "Bingo Bob" Russell | Vice President |
| Tom Skerritt as | Chris Carrick | Senator from Idaho |
| Guest Starring | ||
| NiCole Robinson as | Margaret | Hooper (last name) / Assistant to Chief of Staff |
| Renée Estevez as | Nancy | Aide |
| Erinn Carter as | Laura | Aide to Vice President |
| Co-Starring | ||
| Melissa Fitzgerald as | Carol | Fitzpatrick (last name) Assistant to the Press Secretary |
| Peter James Smith as | Ed | Congressional Liaison |
| William Duffy as | Larry | Congressional Liaison |
| David O. Katz as | Staffer #1 | |
| Jamie Millhoff as | Staffer #2 | |
| Tom W. Chick as | Gordon | Reporter |
| Joyce Guy as | Charlayne | Reporter |
| Becky Meister as | Sally | Reporter |
| Timothy Davis-Reed as | Mark | O'Donnell (last name) / Reporter |
| Teresa Huang as | Holly | Aide to Vice President |
| Matthew Lang as | Staff Assistant | |
| Eric Lemler as | Nat | Intern |
| Karen Goberman as | Researcher |
"I love the personal-relationship side of C.J.," she [Allison Janney] says with a chuckle. "I think I've got the press briefings down pretty much, and I'd love to get into some complicated relationship scenarios."
"Allison Janney is the softer side of C.J. Cregg"
by Jay Boyar
July 29, 2003
Orlando Sentinel
Adding to the realism, the new vice president, played by Gary Cole, will be in place by episode four or five, and around more than predecessor Tim Matheson."He needs to be brought up to speed," Wells says of the character. "He's also very ambitious."
"'West Wing's' fifth season: Politics NOT as usual "
by Jill Vejnoska
September 24, 2003
Atlanta Journal-Constitution
Richard Schiff was even more effusive about the show's direction. The absence of Sorkin's "romantic lyricism," he said, has paralleled the post-honeymoon phase of "the real White House." He called the series a "reality-driven drama now," explaining that "this is why Leo isn't as attractive a character as he might have been last year and why Josh and Toby get into fights."
"'West Wing' cast is upbeat"
by Matthew Gilbert
January 16, 2004
Boston Globe
And one of the main reasons is Leo McGarry, whose character lately has shown signs of being more the tough, demanding boss and aide that he was when "The West Wing" premiered....
And now I'm thinking that the "new" Leo makes a lot more sense than the old one, who'd had his edges softened over the years in ways that sometimes strained credulity.
"You're not the only person who's said this," Spencer said recently when I asked about the pricklier Leo during a "West Wing" press session in Hollywood. A visitor to the set had told Spencer, " 'Leo's gotten so mean,' " he said.
"And you know, mean and nice and all of that is in the eye of the beholder. But I think you have to look to Qumar" and the plot line last season in which Leo helped talk President Bartlet (Martin Sheen) into assassinating a leader of that fictional Middle Eastern country.
"Things were not easy in the White House at the beginning of this season. I mean, fictionally," he said. "And a lot of it fell on Leo's head, an unhappy staff, a president that was miserable and had lost his daughter, and a first lady who could no longer communicate with me and said that she didn't want me in the house any longer. So Leo's been going through a lot of stuff."
...
But isn't it a bit more realistic for Leo, as a chief of staff, to be a tougher guy?
"I think so," he said. "I feel the Leo of today is closer to the Leo of the first half of the first season when [producers Tommy Schlamme and Sorkin] said my characterization of Leo McGarry was like if Casey Stengel was the chief of staff of the White House," he said. So, "yeah, it's a big responsibility, and he's gruff."
"It's good to have irascible Leo back"
by Ellen Gray
February 11, 2004
Philadelphia Daily News
Bailey's move to the VP's office, where his opinions stand out more succinctly, was made, [Alex] Graves says, "because part of the genesis of the character is he's not to be kept out of a room, he's too valuable."
"Josh Malina has been clever add to West Wing"
by Bridget Bynre
April 19, 2004
Canadian Press
Parker was asked why her character, lobbyist Amy Gardner, seemed to disappear from "The West Wing." Parker's last appearance on the show was in October 2003, when she incurred the anger of President Bartlet (Martin Sheen) over a domestic-violence bill.Her departure had as much to do with her pregnancy (she gave birth to son William Atticus in January 2004) as anything else, the "Angels in America" Emmy winner says. "At a certain point, I couldn't, like, stand behind a desk anymore and hold a file. You know, it just got to be ludicrous."
"Parker Returning to 'West Wing'"
January 8, 2005
zap2it.com
Dirty little secret: Personally, [Bradley] Whitford wanted his character to end up with Amy Gardner (Mary-Louise Parker) rather than Donna Moss (Janel Moloney).
May 14, 2006
Washington Post
People were always like, "You stole Josh from Donna!" [Laughs] The only person who doesn't feel that way, actually, is Brad[ley Whitford], who is like, "I should have ended up with you." But I loved doing that part. It was supposed to be just one episode, but it turned into more. - Mary-Louise Parker
" Weeds' Mary-Louise Parker Makes a Killer Bride"
by Matt Webb Mitovich
March 2, 2007
TV Guide Online