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 Timothy Busfield Danny Concannon Guest Star Renee Estevez Nancy Guest Star Charley Lang Congressman Skinner Guest Star Allison Smith Mallory O'Brien Guest Star Tim Matheson Vice President John Hoynes Guest Star Kathryn Joosten Mrs. Landingham Guest Star NiCole Robinson Margaret Guest Star Devika Parikh Bonnie Guest Star Aaron Sorkin Executive Producer Thomas Schlamme Executive Producer John Wells Executive Producer Kristin Harms Producer Llewellyn Wells Producer Ron Osborn Writer Jeff Reno Writer Alan Taylor Director