Mark Harmon NCIS Special Agent Leroy Jethro Gibbs Actor Sasha Alexander NCIS Special Agent Caitlin Todd Actor Michael Weatherly NCIS Special Agent Anthony "Tony" Dinozzo Actor Pauley Perrette Forensic Specialist Abby Sciuto Actor Sean Murray NCIS Special Agent Timothy McGee Actor David McCallum Dr. Donald "Ducky" Mallard Actor Elizabeth Peña FBI Agent Lina Reyes Guest Star Brian Dietzen Jimmy Palmer Guest Star Mary Page Keller Lt. Cmdr. Michaela 'Micki' Shields Guest Star Sean O'Bryan David Shields Guest Star Amanda Fuller Jen Shields Guest Star David Henrie Willy Shields Guest Star Alex Alexander Sara Turcott Guest Star Rebecca Staab Greta Boyen Guest Star Tim Ryan Greg Boyen Guest Star Jesse Head Lyle Chamber Guest Star Bobby Neely Roland Alan Moore Guest Star Donald P. Bellisario Executive Producer Roger Director Director Jeff Woolnough Writer