Rob Lowe Sam Seaborn Actor Martin Sheen President Josiah "Jed" Bartlet Actor Bradley Whitford Dep. Chief of Staff Josh Lyman Actor John Spencer Chief of Staff Leo McGarry Actor Richard Schiff Communications Dir. Toby Ziegler Actor Allison Janney Press Secretary Claudia Jean "C.J." Cregg Actor Dulé Hill Charlie Young Actor Janel Moloney Donna Moss Actor Stockard Channing Abigail "Abbey" Bartlet Actor Matthew Modine Marco Arlens Guest Star Donald Moffat Talmidge Cregg Guest Star Verna Bloom Molly Lapham Guest Star Betsy Aidem Libby Lapham Guest Star Terry Beaver Lee Voight Guest Star Kris Murphy Katie Witt Guest Star Aaron Sorkin Executive Producer Thomas Schlamme Executive Producer John Wells Executive Producer Neal Ahern Jr. Producer Paul Redford Producer Kristin Harms Producer Llewellyn Wells Producer Jon Robin Baitz Writer Alex Graves Director