Donnatella "Donna" Moss – Janel Moloney: Senior Assistant to Josh Lyman (Seasons 1–6); Media Specialist and Press Secretary, Bob Russell for President Campaign (Season 6); Press Secretary, Santos-McGarry Campaign (Season 7); First Lady's Chief of Staff (Season 7).
Annabeth Schott – Kristin Chenoweth: Deputy Press Secretary for Media Relations (Season 6); Campaign staffer, Santos/McGarry Campaign (Season 7); First Lady's Press Secretary (Season 7).
Madeline "Mandy" Hampton – Moira Kelly: Political consultant during Bartlet's first campaign. Worked as a media consultant at Lennox-Chase after the campaign. Briefly consults for Democratic Senator Lloyd Russell before being hired by the White House as a political consultant and Media Director (Season 1). Disappears after the first season of The West Wing and is never mentioned again.
Angela Blake – Michael Hyatt: Worked for Leo McGarry while he was Secretary of Labor. While a political consultant, she is hired to be Director of Legislative Affairs (Season 5). Vanishes after the budget crisis is over and Josh Lyman regains his effective leadership, and is never mentioned again.
Amelia "Amy" Gardner – Mary-Louise Parker: Head of the Women's Leadership Coalition and influential women's rights activist. Works as a political consultant for Senator Howard Stackhouse when he runs for President. Later hired as the Chief of Staff for the Office of the First Lady. Resigns after she upsets the President (Seasons 3–5). Agrees to become the Director of Legislative Affairs in the Santos Administration (Season 7).
Deborah "Debbie" Fiderer – Lily Tomlin: The President's executive secretary. Hired after the death of Mrs Landingham (Seasons 4–7). Charlie arranges for her first interview with the President, where she is groggy from prescription medication and behaves ridiculously, and pushes successfully for her to be re-considered afterwards. When President Bartlet learns the reason she lost her previous White House job—she defied the Director of Personnel by hiring Charlie rather a wealthy Bartlet supporter's unqualified son—and sees she is actually very smart and capable (if still odd), he hires her on the spot.
Margaret Hooper – NiCole Robinson: Assistant to Chiefs of Staff Leo McGarry (Seasons 1–6) and C.J. Cregg (Seasons 6–7). Is pregnant in Season 6, with no clear information about the father, and her baby is never seen on the show.
Nancy – Renée Estevez: President's Confidential Assistant (Seasons 1–7). Estevez is the daughter of Martin Sheen, who plays the President.
Ed – Peter James Smith: White House staffer. Usually seen with Larry.
Larry – William Duffy: White House staffer. Usually seen with Ed.
Ryan Pierce – Jesse Bradford: White House intern assigned to Josh. The nephew of a powerful senator. Related to the 14th President of the United States Franklin Pierce (Season 5). Alternates between reasonable ambition and inappropriate behavior, driven by Josh deliberately being rude and dismissive to him. Becomes a top aide to a Democratic Congressman who Josh hates by the end of Season 5, and is never seen or mentioned afterwards.
Curtis Carruthers – Ben Murray: Succeeds Charlie Young as personal aide to the President (Season 6).
Office of the White House Counsel
Lionel Tribbey – John Larroquette: The fourth White House Counsel of the Bartlet administration, but the first to appear in the series. He is shown to have extremely liberal views and to be incredibly animated and theatrical in his displeasure that the President tends to be more moderate in action. Argues with Sam and Ainsley over Gilbert & Sullivan.
Oliver Babish – Oliver Platt: The fifth and final White House Counsel of the Bartlet administration, but the second of the only two characters to be shown in that position during the series. He first appears advising President Bartlet when the President is considering revealing his diagnosis of multiple sclerosis to the public. He appears connected to this plot-line into season three, then returns to the series in season seven to participate in the White House's internal investigation into the military shuttle leak. He is later mentioned by Santos as a potential choice for Attorney General.
Ainsley Hayes – Emily Procter: Associate (and proposed Deputy) White House Counsel (Seasons 2–3). Conservative (although not evangelical) Republican from North Carolina. Graduate of Harvard Law School (with Cliff Calley, the Republican lawyer who is the majority counsel on the House Government Reform & Oversight Committee during Leo McGarry's testimony). After she soundly defeats and embarrasses Sam during a debate on the political talk show Capital Beat, President Bartlet tells Leo McGarry to offer her a job, which she initially thinks is either a joke or a terrible idea, but seeing the staff in action and her friends' ugly anti-Bartlet comments leads her to accept the Associate White House Counsel's post. Briefly reappears in Season 7, wanting to become White House Counsel for the Santos Administration.
Joe Quincy – Matthew Perry: Associate White House Counsel (Seasons 4–5). Republican. Uncovers Vice President Hoynes's leaking of information in his affair with local socialite, Helen Baldwin, ultimately leading to Hoynes' resignation. He is later tasked by Toby to find out if the Supreme Court's ailing Chief Justice would be willing to resign, which he has strong ethical objections about doing because he clerked for the Chief Justice and reveres him despite their polar-opposite political views, but he does what Toby asked him to.
Mike Wayne – Benjamin Brown: Associate White House Counsel (Season 4–7). Is consulted by Toby and Josh in regards to dealing with a chemical company executive (who is Toby's former roommate) who wants to revise his written testimony to the House Committee on Natural Resources and seeks whistle blower status protections. Deals with Toby after he admits to being the source of the military space shuttle leak.
Richard Squire – Michael Kostroff: Associate White House Counsel (Season 6). Graduate of Yale Law, and a Rhodes Scholar.
Lieutenant General Alan Adamle – Gerald McRaney: A three-star general in the USAF. Meets with Leo to discuss the International Criminal Court in episode (3.05) and stuns Leo by revealing Leo once (completely inadvertently) bombed a non-military target and killed innocent civilians. Also briefs then President-elect Bartlet on a small delegation of military advisers being sent to the Philippines three days after the presidential election in episode (5.22). Served with Leo in Vietnam.
General Shannon – Daniel Von Bargen: Appears in episodes (2.01) and (2.10). A four-star general in the USAF; Leo calls him "Jack" in his first episode and "Ken" in his second appearance. He seems to be the senior officer in the Situation Room in (2.01) until Nancy McNally arrives.
General Ed Barrie – Tom Bower: Army Chief of Staff. Appears in episode (2.05) berating C.J. for reprimanding his intentions to criticize the President on TV before his retirement, but is left silent when C.J. tells him is wearing award ribbons and decorations he has not earned; President Bartlet, however, later says the General served his country bravely and would face no White House censorship of any of his views.
General Mitch Jensen – Christopher Kriesa: A three-star Army general. Present in the Situation Room during discussions of retaliatory options to Morris Tollivers' USAF medical transport being shot down in episode (1.03). Also advises the President on the India-Kashmir crisis in (1.11) and (1.12).
Colonel Mark Chase – David Graf: Air Force officer who advises Leo on a crisis with Iraqi oil smugglers in (2.07), and monitors the Missile Defense Shield test in (2.12).
CIA Director George Rollie – Ryan Cutrona: President Bartlet does not trust or like him, but as C.J. and Toby note in 365 Days, his pariah status is useful because it prevents the President from tearing down anyone else during tense situations.
Mr. Cashman – often mentioned alongside Secretaries Hutchinson and Berryhill, implied to be a senior official at one of the Executive Branch departments, the department of either State or Defense (Seasons 1–2).
Bobby Dunn – Gary Cervantes: Appears in (1.11), (1.22), (2.01), (2.10), and (2.21); apparently a State Department official.
Albie Duncan – Hal Holbrook: Assistant Secretary of State (office unstated). Longtime Republican and State Department elder (more than 40 years); is brought in by Leo (to the President's displeasure) to counsel the President on the submarine crisis off of North Korea in episode (3.06); later brought in by Toby during the reelection campaign to help C.J. spin the post-debate in episode (4.06).
Mike Chysler – Glenn Morshower: (occasionally 'Jack'); adviser to the President during his first term, regularly appearing in the Situation Room. Briefs the President on the DEA hostage crisis; also advises the President during the prelude to the assassination of Abdul Shareef near the end of Season 3. Appears in Seasons 2-4
Mike Casper – Clark Gregg: FBI Special Agent, usually acting White House liaison (Seasons 2–5).
Bruno Gianelli – Ron Silver: a political operative and consultant introduced in the third season as the campaign manager of Bartlet's 2002 bid for reelection, and continues in this role through the fourth season. His unmatched track record of victories includes a House district that no Democrat has won for decades, several different US senators & state governors, as well as a win for an unspecified Israeli prime minister. The character reappears as Eric Baker's campaign manager for the 2006 Democratic primary, only to become an independent consultant to Republican nominee Arnold Vinick after Baker withdraws from the race. The change of political affiliations mirrored Ron Silver's real-world change of party affiliation, as the actor campaigned for President George W. Bush in the 2004 presidential election.
Josephine "Joey" Lucas – Marlee Matlin: Political consultant, pollster often consulted by the White House and Democratic campaigns (Seasons 1–7). The character is deaf, as is Matlin.
Connie Tate – Connie Britton: Bartlet-Hoynes re-election campaign staffer (Season 3); a likable woman who quickly befriends Sam Seaborn. Often wins points by smoothing feathers ruffled by her acerbic co-worker Doug Wegland.
Doug Wegland – Evan Handler: Bartlet-Hoynes re-election campaign staffer and speechwriter (Season 3); he's acerbic and finds himself offside with Toby Ziegler, but ends up winning the staffers' respect with his good ideas and staunch belief in them (particularly his push for a presidential veto on the "death tax" that leads to a major political victory for the administration).
Kevin Kahn – Patrick Breen: Former friend of Sam Seaborn. Staffer on Ritchie's 2002 presidential campaign (Season 3), who ends up humiliating Sam by leaking an attack ad that makes the Bartlet campaign look vindictive and stupid.
Dylan Clark – Tim Kelleher: Hoynes' campaign manager (Season 6).
Louise "Lou" Thornton – Janeane Garofalo: a capable lobbyist with an IQ of 200, described by Santos as having a 'completely different take on the campaign' and by Josh as knowing 'image stuff backwards and sideways', she only reluctantly agrees to Josh's request to join the Santos-McGarry campaign as Director of Communications, when Santos agrees she can report to him directly. Very tough and experienced, she successfully argues that many loyal Santos campaign operatives are not up to snuff and gets them cut loose, and later tells Josh she doesn't give an inch to rational, sane Republicans because they're still the GOP and the enemy of what she believes is right. With Josh considering her to have enough campaign experience to potentially replace him as Campaign Manager, she acts as Josh's de facto deputy through to the very end, and is then appointed as Santos's Director of Communications (Season 7).
Ronna Beckman – Karis Campbell: Santos's personal assistant. She is present from the very beginning of Matt Santos's campaign for the presidency in season 6, and appears in almost every episode in season 7. In one episode, she mentions that she regards Josh, Annabeth and Lou as her only friends, which Lou claims makes Ronna more pathetic than herself (who hasn't spoken to any of her friends in two months) or Annabeth (who believes she doesn't have friends anymore). In her final appearance, Deborah Fiderer trains her as Santos's executive secretary, warning her never to revoke the First Lady's walk-in privileges, even as the President is certain to request it. She has a relationship with another female staffer (Cindy) on the Santos campaign.
Bram Howard – Matthew Del Negro: Staffer, Santos-McGarry Campaign (Seasons 6–7); Santos Administration counsellor to the President (Season 7).
Ned Carlson – Evan Arnold: Aide to Congressman Santos (Season 6); Staffer, Santos-McGarry Campaign (Seasons 6–7). Ned is reassigned to Santos's Congressional office early in Season 7 with the intention of giving him a spot in the administration after the election, but he does not appear on the series after his dismissal from the campaign.
Otto – Ramon De Ocampo: Speechwriter, Santos-McGarry Campaign (Season 7); Staffer in the Santos Administration (Season 7). Very young but capable man who has a campaign fling with Lou Thornton. Josh irrationally vents his post-election stress and anger at Otto, who is saved when Sam Seaborn shuts Josh's behavior down permanently; it is implied he will have a speechwriting role in the Santos Administration.
Sheila Brooks – Patricia Richardson: Senator Vinick's chief of staff and Vinick-Sullivan campaign manager; She, like Vinick, is portrayed as level-headed and not overtly partisan. Often at odds with the more conservative voices in the party, she leaves the campaign weeks before election day to placate the Republican base (Season 6–7). In her (and Vinick's) final appearance, Brooks is mentioned as possibly being hired as Chief of Staff to the Republican Senate Majority Leader, and she makes an argument that convinces the Senator that he shouldn't run for President again—and that he should accept President-elect Santos' offer to become the next Secretary of State.
Jane Braun – Melinda McGraw: Vinick-Sullivan campaign manager after Brooks' resignation (Season 7); A very conservative activist who replaces Shelia in order to energize hard-core GOP voters, but also disgusts everyone by attempting to make an election night issue of Leo McGarry's death. Her outspoken partisanship puts her at odds with both Vinick and Bruno Gianelli.
Bob Mayer – Stephen Root: Vinick-Sullivan speechwriter (Season 6–7). Frequently mocked for his messy eating habits but extremely smart and effective (and, like Vinick and Sheila Brooks, level-headed in his conservatism), Mayer becomes fast friends with Gianelli. On election night, the two briefly discuss forming a consulting firm when Mayer firmly declares he is never going to become involved in daily governance, but Gianelli politely declines because the campaign life has worn him down and he plans to retire to his home in upstate New York.
Greg Brock – Sam Robards: White House correspondent for the New York Times . Greg Brock is also the name of a real editor for the New York Times. One of the most regularly referred to White House correspondents, second only to Danny Concannon. Writes a story written that alleges the existence of a classified military space shuttle which could be used to help three astronauts on the International Space Station who are running out of oxygen. His source is initially suspected to be C.J. Cregg, whose phone records show a surprisingly large number of calls to Greg Brock. Brock goes to jail after being held in contempt of court for failing to reveal the name of his source. White House Communications Director Toby Ziegler eventually confesses to the leak, saying that he acted alone, and that Brock was the only reporter to whom he leaked the information. The storyline regarding the leak and subsequent investigation has been compared by some to the Valerie Plame affair. (Seasons 5-7).
Roger Salier – Ivan Allen: Television anchor on News Center 4 (Seasons 1–7).
Mark Gottfried – Ted McGinley: Talk show host of "Capitol Beat" (Episodes 2.04, 2.13 & 2.14).
Diane Mathers – Kathrin Middleton: Tough talk show host who interviews Zoey Bartlet about her kidnapping and John Hoynes about his intentions to run for President again (Episodes 5.07 & 6.07).
Taylor Reid – Jay Mohr: Conservative talk show host, baits C.J. Cregg by calling her a "chicken" (Season 5). Some reviewers have likened the character to Bill O'Reilly, the combative host of the news commentary show The O'Reilly Factor. (Season 5)
Katarina "Katie" Witt – Kris Murphy: White House Press Corps Reporter (Seasons 1–7).
Mark O'Donnell – Timothy Davis-Reed: White House Press Corps Reporter. Episode 3:08 - says he is from Canada. (Season 2-7)
Doug Westin – Steven Eckholdt: Liz's husband. Neither the President or his senior staff think much of him: the President because he doesn't think Doug is really worthy of marrying Elizabeth, the staff because they view him as an empty suit. Has an adulterous affair with the family's nanny exposed and unsuccessfully runs for the House of Representatives representing New Hampshire in 2006 (Seasons 5–7).
Vic Faison – Ben Weber: Ellie Bartlet's husband (Season 7).
Annie Westin – The President's granddaughter and Elizabeth Bartlet Westin's daughter. Aged 12 in Season 1. (Season 5, Episode 1)
Gus Westin – Michael Krepack: The President's grandson and Elizabeth Bartlet Westin's son. (Season 5)
Molly Lapham Cregg – Verna Bloom: C.J.'s stepmother and her former high school English teacher (Season 4)
Talmidge Cregg – Donald Moffat: C.J.'s father, a retired math teacher with Alzheimer's disease. (Season 4)
Grammy Cregg – Mentioned as the Midwestern source of C.J.'s 'Hay is for Horses' witticism.
Two older brothers- Mentioned in The Black Vera Wang.
Josh Lyman's family
Joanie Lyman – Josh's older sister who died in a fire when she was babysitting him.
Noah Lyman – Josh's father, a hugely successful lawyer and longtime Democratic Party supporter, who was good friends with Leo McGarry. Died on the night of the Illinois primary (during Bartlet's first presidential campaign).
Mrs. Lyman – Josh's mother and only living relative. She lives in Florida and Josh usually goes down to visit her during holidays.
Mother – Comes to visit when Donna is hospitalized in Germany after the Gaza attack.
Will Bailey's family
Elsie Snuffin – Danica McKellar: Will Bailey's stepsister, an undiscovered comedy writer. The character is named after the birth name of the actress Kayla Blake, a cast member of Sorkin's previous show Sport's Night. (Season 4)
Mrs. Young – Charlie's mother, a Washington D.C. police officer who was shot and killed in the line of duty prior to the start of the series, by a gunman who was never arrested. (mentioned, seen only in a photo)
Matt Santos's family
Helen Santos – Teri Polo: Matt Santos's wife (Season 6–7)
Peter Santos – Matt Santos's son (Season 6-7)
Miranda Santos – Matt Santos's daughter (Season 6-7)
Jorge Santos – Matt's Santos's brother (Season 7), a failure in life who nearly ruins his brother's presidential bid when the Vinick campaign thinks they have evidence Matt Santos has an illegitimate child (in fact, Matt discovered that Jorge refused to support his ex-girlfriend, and therefore set up secret payments to help her on his own).
Laurie – Lisa Edelstein: Sam Seaborn's friend. Law student working as a call girl (Season 1 and mentioned several times in 2).
Al Kiefer – John de Lancie: Democratic pollster who had a short relationship with Joey Lucas. The senior staff can't stand him and when Joey's abilities became apparent, she takes over his previous role as the Bartlet Administration's top pollster. (Season 1)
Larry Claypool – John Diehl: Freedom Watch lawyer (Seasons 1, 4) who spends his time filing lawsuits against President Bartlet and his staff in hopes of bringing down the administration.
Bernard Thatch – Paxton Whitehead (Ep 2.10, Ep 6.07): Head of the White House Visitor's Office.
Ann Stark – Felicity Huffman (Ep 2.11): Toby Ziegler's former friend, until she betrays him when he tries to broker a compromise on patients' rights. Chief of Staff to the Senate Majority Leader.
Lisa Sherborne – Traylor Howard (Ep 3.11): Sam Seaborn's former fiancée who now works for Vanity Fair. Sam broke off their engagement because he wanted to leave the New York scene and work at the White House.
Dr. Stanley Keyworth – Adam Arkin: Therapist specializing in trauma cases. He is asked by Leo McGarry to see Josh after Josh yells at the President. Staff Therapist for the American Trauma Victims Association (ATVA) Has several sessions as the President's therapist as well. (Seasons 2–4)
Jordon Elaine Kendall – Joanna Gleason: Leo McGarry's lawyer during the Bartlet MS hearings and love interest for several months. (Season 3–4)
Alana Waterman – Lee Garlington: Toby Ziegler's attorney, called upon when Toby confesses to the White House leak. (Season 7)
Jean Paul Pierre Claude Charpentier, Vicomte de Condé de Bourbon – Trent Ford: Zoey Bartlet's French boyfriend. (Season 4)
Colin Ayres – Jason Isaacs: Photographer who has a fling with Donna Moss in Gaza. (Season 5–6)
Lt. Colonel Gantry, pilot of Air Force One, heard several times on personal announcements on the plane.
Colonel Jesse Weisskopf, pilot of Air Force One, seen in the episode 'Angel Maintenance' (Season 4) informing the President on the status of the plane.
Dr. Millicent Griffith – Mary Kay Place (Ep. 2.15, Ep. 6.08, Ep. 6.09; mentioned in Ep. 2.18): Close family friend of the Bartlets, Ellie's godmother, occasional medical adviser to the President, and President Bartlet's Surgeon General.
Reverend Don Butler - Don S. Davis: A conservative televangelist from Virginia, who is a candidate for the Republican Party's nomination for President of the United States in the 2006 election, but is defeated by Arnold Vinick and politely declines Vinick's offer of the Vice President spot because he cannot support Vinick's pro-choice positions.
Bobby Zane – Noah Emmerich (Ep. 1.14) Defense lawyer for a convicted murderer and high school bully of Sam Seaborn. He contacts Sam in order to persuade the White House to commute his client's death sentence.
Marco - Matthew Modine Appears in the episode "The Long Goodbye" (Ep. 4.13). A high school classmate of C. J. Cregg who helps her deal with her father's steady mental decline due to Alzheimer's disease.
Morris Tolliver - Ruben Santiago-Hudson Appears in the episode "Post Hoc, Ergo Propter Hoc" (Sea 1, Ep 2). He was a physician and Navy officer (Captain), who served as a temporary replacement at the position of Physician to the President of the United States. Despite his relatively low rank for the position, Jed Bartlet liked him and Leo McGarry asked him to stay on full time. Before he could assume the position, however, a plane he was on during a diplomatic mission was shot down over the Middle East, which prompted the President to "overreact" in the next episode "A Proportional Response". Dr. Tolliver was married to Angela and their daughter's name was Cory. The child was named for her great-grandmother, who had been named after her great aunt, who got it from the first free woman she ever met.
Gail: C.J. Cregg's pet goldfish. A gift from Danny Concannon. In the season 1 episode "The Short List," Josh Lyman tells Danny that C.J. likes "goldfish." Although Josh is referring to snack crackers of the same name, Danny mistakenly believes he is referring to the aquatic creature; after giving C.J. the fish, Danny mentions that the pet-store owner had named it "Gail." On the DVD commentary track for episode 14, "In Excelsis Deo," Aaron Sorkin, Thomas Schlamme, and Alex Graves mention that the prop masters created a miniature Christmas ornament to place on the floor of Gail's fish bowl and that from then on, the prop masters often crafted tiny decorations related to the themes in a given episode, for example when hostilities were escalating in India and Pakistan, the bowl contained a tiny bomb shelter. They also mention that many scenes set in C.J.'s office throughout the succeeding seasons include shots of Gail's bowl and that as of the commentary's recording at the end of season four, the prop masters insisted that the specific goldfish used had never been replaced.
^Joel Brown, New York Times Syndicate. "Time for first clips from 'Barbershop'," Ventura County Star (CA), February 25, 2004, "Life, Arts, and Living" section, page 4: "...C.J. takes another turn jousting with obvious Bill O'Reilly clone Taylor Reid (guest star Jay Mohr)."