Martin Sheen President Josiah "Jed" Bartlet Actor John Spencer Chief of Staff Leo McGarry Actor Rob Lowe Sam Seaborn Actor Bradley Whitford Dep. Chief of Staff Josh Lyman Actor Richard Schiff Communications Dir. Toby Ziegler Actor Allison Janney Press Secretary Claudia Jean "C.J." Cregg Actor Moira Kelly Mandy Hampton Actor Dulé Hill Charlie Young Actor Janel Moloney Donna Moss Actor Lisa Edelstein Laurie Guest Star F. William Parker Rev. Al Caldwell Guest Star Allison Smith Mallory O'Brien Guest Star Suzy Nakamura Cathy Guest Star Marc Grapey Billy Guest Star Kathryn Joosten Mrs. Landingham Guest Star NiCole Robinson Margaret Guest Star Devika Parikh Bonnie Guest Star David Sage John Van Dyke Guest Star Peter James Smith Ed Guest Star Annie Corley Mary Marsh Guest Star Aaron Sorkin Executive Producer Thomas Schlamme Director John Wells Executive Producer Kristin Harms Producer Llewellyn Wells Producer