NCIS season 21: next episode, cast and everything we know about the drama

Katrina Law, Sean Murray, Rocky Carroll and Gary Cole in NCIS
Katrina Law, Sean Murray, Rocky Carroll and Gary Cole in NCIS (Image credit: CBS)

NCIS has become one of the most historic TV franchises of all time, with numerous spinoffs that have aired on CBS over the years. But the flagship series remains, as NCIS season 21 continues its run on CBS.

Despite the show being old enough to buy a beer, NCIS is still among CBS's top-rated shows. It has also outlasted two of its spinoffs — NCIS: New Orleans ran for seven seasons and NCIS: Los Angeles concluded its run in 2023 after 14 seasons — but it still has a running mate in NCIS: Hawai'i, which is heading into its third season this upcoming TV season, and a new spinoff, NCIS: Sydney, that premiered in 2023; plus, another one on the way in NCIS: Origins, a prequel series.

Fun fact, with NCIS season 21, the franchise becomes the third-longest running US primetime drama series ever, only trailing Law & Order and Law & Order: SVU.

With NCIS season 21 officially underway, here is everything that we know about NCIS season 21.

NCIS season 21 next episode

NCIS season 21 wraps up its abbreviated 10-episode season on Monday, May 6, with the season finale airing at 9 pm ET/PT on CBS. Here is the synopsis for the finale, titled "Reef Madness":

"Parker and Knight discover three bodies on an old Navy ship that’s about to be sunk and turned into an artificial reef, when they’re suddenly locked inside by a mysterious figure. Also, Vance offers Knight a unique opportunity."

The crime drama is joined on CBS Monday nights by its spinoff series NCIS: Hawai'i season 3 and a pair of CBS's long-running comedies, The Neighborhood season 6 and Bob Hearts Abishola season 5.

Check out our post on how to watch NCIS season 21 for full details, but in a nutshell you need to have access to CBS, whether that's through traditional TV setups, live TV streaming services or Paramount Plus.

NCIS season 21 cast

Most of the familiar faces of NCIS are set to be back for season 21, that includes:

  • Sean Murray as Timothy McGee
  • Wilmer Valderrama as Nick Torres
  • Brian Dietzen as Jimmy Palmer
  • Diona Reasonover as Kasie Hines
  • Katrina Law as Jessica Knight
  • Rocky Carroll as Leon Vance
  • Gary Cole as Alden Parker

Mark Harmon was the longtime face of NCIS, but his character Gibbs was written out of the show in season 19. However, there have been rumors that Harmon could return to the series at some point in the future, though when and how is unknown. 

Also, as mentioned above, with the passing of David McCallum, the show has lost another fan favorite character, Donald "Ducky" Mallard.

NCIS season 21 plot

NCIS follows the Naval Criminal Investigative Service in Washington, D.C. While there are some storylines that continue over a long period of time, the show is mostly a case-of-the-week procedural structure.

However, there is at least one storyline that we're presumably going to see be picked up when the new season begins. The NCIS season 20 finale ended in dramatic fashion with a moment involving Nick Torres (Wilmer Valderrama). While doing an undercover stint in prison to help get info on a dangerous Russian agent, Torres spotted someone from his past. We learn that this man likely abused Torres or someone close to him when he was younger. Once Torres is out of prison, he goes to the man's home and pulls a gun on him, saying that he wants to watch him die.

Does Torres kill the man? We'll have to wait until season 21 to get the answer.

NCIS season 21 trailer

There is no trailer for NCIS season 21 at this time. As soon as there is one, we'll make sure to include it here. 

Michael Balderston

Michael Balderston is a DC-based entertainment and assistant managing editor for What to Watch, who has previously written about the TV and movies with TV Technology, Awards Circuit and regional publications. Spending most of his time watching new movies at the theater or classics on TCM, some of Michael's favorite movies include Casablanca, Moulin Rouge!, Silence of the Lambs, Children of Men, One Flew Over the Cuckoos Nest and Star Wars. On the TV side he enjoys Only Murders in the Building, Yellowstone, The Boys, Game of Thrones and is always up for a Seinfeld rerun. Follow on Letterboxd.