Donald P. Bellisario Creator, Executive Producer Don McGill Creator Mark Harmon NCIS Special Agent Leroy Jethro Gibbs Actor, Executive Producer Sean Murray NCIS Special Agent Timothy McGee Actor Wilmer Valderrama NCIS Special Agent Nicholas "Nick" Torres Actor Brian Dietzen Dr. Jimmy Palmer Actor Diona Reasonover Forensic Scientist Kasie Hines Actor Katrina Law NCIS Special Agent Jessica Knight Actor Rocky Carroll NCIS Director Leon Vance Actor, Director David McCallum Dr. Donald "Ducky" Mallard Actor Gary Cole FBI Special Agent Alden Parker Actor Pam Dawber Marcie Warren Guest Star Katherine Cortez Thelma McKeever Guest Star Joe Spano Tobias "T.C." Fornell Guest Star Laura San Giacomo Grace Confalone Guest Star Jason Wiles Tom Samuels a.k.a. Paul Lemere Guest Star Valarie Pettiford Sonia Eberhart Guest Star Randall Batinkoff Walt Freeman Guest Star John Hensley Phil Hanover Guest Star Tess Aubert Piper Guest Star Erik Passoja FBI Deputy Director Wayne Sweeney Guest Star Karina Noelle Castillo FBI Agent Ramirez Guest Star Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Frank Cardea Executive Producer George Schenck Executive Producer Steven D. Binder Executive Producer Scott Williams Executive Producer, Writer Christopher J. Waild Writer Marco Schnabel Writer Michael Zinberg Director Terrence O'Hara Director Brendan Fehily Writer Katherine Beattie Writer David J. North Executive Producer James Whitmore Jr. Director