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 David McCallum Dr. Donald "Ducky" Mallard Actor Pam Dawber Marcie Warren Guest Star Katherine Cortez Thelma McKeever Guest Star Dave Florek Virgil McKeever Guest Star Travis Hammer Faux County Deputy Randall Sledge Guest Star Terryn Westbrook County Deputy Regina Unger Guest Star Jeniffer Behrens Marta Jimenez Guest Star Derek Chariton Lonny Guest Star Allie Davis Sandy Guest Star Colin Land NCIS Special Agent Brent Hollister 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 Donald P. Bellisario Executive Producer Christopher J. Waild Writer Michael Zinberg Director