Don McGill Creator Donald P. Bellisario Creator, 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 Gary Cole FBI Special Agent Alden Parker Actor Vanessa Lachey Special Agent Jane Tennant Guest Star Noah Mills Special Agent Jesse Boone Guest Star Chris O'Donnell Special Agent Grisha Callen Guest Star LL Cool J Special Agent Sam Hanna Guest Star Robert Picardo Retired Marine Gunnery Sergeant Dale Harding Guest Star Brianna Reed Libby Guest Star Tim Rock Fletc Instructor Cambria Guest Star Stephanie Hodge Greta Ford Guest Star Kevin Changaris Simon Williams Guest Star Joe Chambrello Kidnapper Guest Star Chas. Floyd Johnson Executive Producer Mark Horowitz Executive Producer Mark Harmon Executive Producer Frank Cardea Executive Producer George Schenck Executive Producer Steven D. Binder Executive Producer Scott Williams Executive Producer Christopher J. Waild Writer Michael Zinberg Director