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 Spencer Treat Clark Ryan Smith Guest Star Joshua Cox Navy Capt. Paul Smith Guest Star Carol Locatell Renee Prewdome Guest Star Presilah Nunez Navy Lt. Cmdr. Cheryl Stanley Guest Star Jonathan Medina Navy Cmdr. Ted Morgan Guest Star Joe Alvarez Fire Lt. Earl Davis Guest Star Matt Jayson Edgar Stump 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, Writer Donald P. Bellisario Executive Producer Terrence O'Hara Director