Mark Harmon NCIS Special Agent Leroy Jethro Gibbs Actor, Executive Producer Sean Murray NCIS Special Agent Timothy McGee Actor Emily Wickersham NCIS Special Agent Eleanor "Ellie" Bishop Actor Wilmer Valderrama NCIS Special Agent Nicholas "Nick" Torres Actor Maria Bello Special Agent Jacqueline "Jack" Sloane Actor Brian Dietzen Dr. Jimmy Palmer Actor Diona Reasonover Forensic Scientist Kasie Hines Actor Rocky Carroll NCIS Director Leon Vance Actor David McCallum Dr. Donald "Ducky" Mallard Actor Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Frank Cardea Executive Producer, Writer George Schenck Executive Producer Steven D. Binder Executive Producer Scott Williams Executive Producer, Writer Donald P. Bellisario Executive Producer Diana Valentine Director