Mark Harmon NCIS Special Agent Leroy Jethro Gibbs Actor, Executive Producer Pauley Perrette Forensic Specialist Abby Sciuto Actor Sean Murray NCIS Special Agent Timothy McGee Actor Wilmer Valderrama NCIS Special Agent Nicholas "Nick" Torres Actor Jennifer Esposito NCIS Special Agent Alexandra "Alex" Quinn Actor Emily Wickersham NCIS Probationary Agent Eleanor "Ellie" Bishop Actor Brian Dietzen Dr. Jimmy Palmer Actor Duane Henry MI6 Officer Clayton Reeves Actor Rocky Carroll NCIS Director Leon Vance Actor David McCallum Dr. Donald "Ducky" Mallard Actor Vernee Watson Miss Helen Frimkes Guest Star John Kapelos Victor Castor Guest Star Braden Lynch Neal Sherwood Guest Star Joshua LeBar Adam Cooper Guest Star Devin Sidell Angela Russell Guest Star Amy Gumenick Katrina Cooper Guest Star Mike Falkow Jim Bruno Guest Star Conner Marx Milo Torbush Guest Star Gary Glasberg Executive Producer Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Frank Cardea Executive Producer George Schenck Executive Producer Steven D. Binder Executive Producer, Writer Scott Williams Executive Producer Donald P. Bellisario Executive Producer James Whitmore Jr. Director