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 Guy Boyd Stanley Guest Star Elisabeth Moss Zoey Bartlet Guest Star Suzy Nakamura Cathy Guest Star Renee Estevez Nancy Guest Star Sam Lloyd Bob Engler Guest Star Nick Offerman Jerry Guest Star Nicholas Cascone Loomis Guest Star Rachel Singer Marge Guest Star David Fabrizio Jonathan Lacey Guest Star Kathryn Joosten Mrs. Landingham Guest Star NiCole Robinson Margaret Guest Star Aaron Sorkin Executive Producer, Writer Thomas Schlamme Executive Producer John Wells Executive Producer Kristin Harms Producer Llewellyn Wells Producer Anthony Drazan Director