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 Maria Bello NCIS Special Agent Jacqueline "Jack" Sloane Actor Emily Wickersham NCIS Special Agent Eleanor "Ellie" Bishop Actor Brian Dietzen Dr. Jimmy Palmer Actor Rocky Carroll NCIS Director Leon Vance Actor, Director Duane Henry MI6 Officer Clayton Reeves Actor David McCallum Dr. Donald "Ducky" Mallard Actor Margo Harshman Delilah Fielding Guest Star Joe Spano Senior FBI Agent T.C. Fornel Guest Star Diona Reasonover Forensic Scientist Kasie Hines Guest Star Laura San Giacomo Dr. Grace Confalone Guest Star Graham Hamilton Gabriel Hicks Guest Star Alberto De Diego Marine 1st Lt. Ethan Wynn Guest Star Hilary Ward Jessica Shaeffer Guest Star Fran Bennett Mary Elaine Smith Guest Star Clint Culp Roy Baxter Guest Star Tyler Parks Navy Petty Officer 3rd Class Gordon Cooper Guest Star 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, Writer Donald P. Bellisario Executive Producer Christopher J. Waild Writer David J. North Writer Gina Lucita Monreal Writer Brendan Fehily Writer Jennifer Corbett Writer Tony Wharmby Director Michael Zinberg Director Bethany Rooney Director Thomas J. Wright Director