Rank 10: Clayton Reeves
The Top 10 start with Clayton Reeves, whom Duane Henry portrayed in Seasons 13 to 15. He appears in a total of 28 episodes. Although he was never an official team member under Gibbs, he assisted them as a liaison officer (similar to Ziva David) from the English intelligence service MI6 in several cases.
Clayton Reeves’s last episode is the 22nd of Season 15: Someone attempts to kill forensic scientist Abby Sciuto. Ultimately, Reeves dies while trying to save her.
Rank 9: Caitlin Kate
Todd
Kate is one of the first members of Team Gibbs. In Episode 1, she is still working for the Secret Service, but then transfers to the Navy CIS. Within the team, she frequently clashes with her colleague Tony DiNozzo, especially due to his macho behavior. Nevertheless, she appreciates him as a good colleague and maintains a friendly relationship with the other team members, Gibbs and McGee.
At the end of Season 2, Kate is shot by Mossad agent Ari Haswari. Actress Sasha Alexander wanted to leave the series, and Kate was ultimately written out. In the first episodes of Season 3, she still has guest appearances, reaching an episode count of 55.
Rank 8: Alden Parker
Alden Parker joins the team in Season 19. Played by Gary Cole, he succeeds Leroy Jethro Gibbs as the head of the investigative team at NCIS. At the time of this list, he has been involved in 72 episodes. He has also been announced as a cast member for Season 23, which will start in October.
He has now appeared in a total of 181 episodes and is also listed as a cast member for the upcoming Season 23. His episode count will therefore continue to rise starting October 2025.
