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 John Amos Percy Fitzwallace Guest Star Renee Estevez Nancy Guest Star Suzy Nakamura Cathy Guest Star Kathryn Joosten Mrs. Landingham Guest Star NiCole Robinson Margaret Guest Star Rose Rollins Suzanne Guest Star Kim Webster Kim Guest Star Aaron Sorkin Executive Producer Thomas Schlamme Executive Producer John Wells Executive Producer Kristin Harms Producer Llewellyn Wells Producer Marc Buckland Director