NCIS

= Cast =
 * Mark Harmon as Leroy Jethro Gibbs (main: seasons 1–present)
 * Sasha Alexander as Caitlin Todd (main: seasons 1–2; guest: seasons 3, 8–9, and 12)
 * Michael Weatherly as Anthony DiNozzo (main: seasons 1–13)
 * Pauley Perrette as Abby Sciuto (main: seasons 1–15)
 * David McCallum as Dr. Donald "Ducky" Mallard (main: seasons 1-present)
 * Sean Murray as Timothy McGee (main: season 2–present; recurring: season 1)
 * Cote de Pablo as Ziva David (main: season 3 episode 4-season 10, season 11 episodes 1-2; guest: season 3 episodes 1-2, season 16; recurring: season 17)
 * Lauren Holly as Jenny Shepard (main: seasons 3–5; guest: seasons 9 and 12)
 * Rocky Carroll as Leon Vance (main: season 6–present; recurring: season 5)
 * Brian Dietzen as Dr. Jimmy Palmer (main: season 10–present; recurring: seasons 1–9)
 * Emily Wickersham as Eleanor Bishop (main: season 11 episode 12–present; guest: season 11 episodes 9-11)
 * Wilmer Valderrama as Nicholas Torres (season 14–present)
 * Jennifer Esposito as Alexandra Quinn (season 14)
 * Duane Henry as Clayton Reeves (main: seasons 14–15; guest: season 13)
 * Maria Bello as Dr. Jacqueline Sloane (main: season 15–present)
 * Diona Reasonover as Kasie Hines (main: season 16–present; recurring: season 15)

= Seasons =