Martin Sheen President Josiah "Jed" Bartlet Actor Stockard Channing Abigail "Abbey" Bartlet Actor John Spencer Chief of Staff Leo McGarry Actor Bradley Whitford Dep. Chief of Staff Josh Lyman Actor Allison Janney Press Secretary Claudia Jean "C.J." Cregg Actor Richard Schiff Communications Dir. Toby Ziegler Actor Dulé Hill Charlie Young Actor Rob Lowe Sam Seaborn Actor Janel Moloney Donna Moss Actor Joshua Malina Will Bailey Actor Mary McCormack Kate Harper Actor Janeane Garofalo Louise Thornton Actor Jimmy Smits Matthew Santos Actor Teri Polo Helen Santos Actor Alan Alda Senator Arnold Vinick Actor Mary-Louise Parker Amy Gardner Actor NiCole Robinson Margaret Actor Michael O'Neill Secret Service Agent Ron Butterfield Actor Patricia Richardson Sheila Brooks Actor Stephen Root Bob Mayer Actor Kristin Chenoweth Annabeth Schott Actor Karis Campbell Ronna Actor Bonita Friedericy Gail Addison Actor John Wells Executive Producer Tim Matheson Director