NCIS has remained strong over the last two decades and continues to do so as the series prepares to head into its 24th season on the 2026 TV schedule. Even with Mark Harmon’s exit believed to be the “death knell” of NCIS, it’s definitely managed to hold its own. Harmon had joined NCIS as Leroy Jethro Gibbs when it was still just a JAG backdoor pilot, and when it came time to cast the character, a co-creator’s wife made a spot-on prediction about Harmon.
When they were casting for NCIS, plenty of A-listers were being tossed around for the role of Gibbs, such as Harrison Ford. Not surprisingly, Harmon was on the short list for potential actors to play Leroy Jethro Gibbs that CBS had sent out. What is surprising is that one particular person had a feeling that if Harmon got the role, NCIS would go far. Co-creator Don McGill shared on the NCIS: Partners & Probies podcast that his wife actually predicted the show’s success:
So my wife actually is more of a TV person. Like, since she was young, she's been like fan. And so all these names came up, and then Mark's name came up. And I knew who Mark was and where, but my wife was like, ‘Mark Harmon? Summer School?’ And she's like, ‘If you guys get Mark Harmon, it's gonna be a hit. And I was like, ‘Really?’ …. [And I’m like,] ‘Yeah, well, okay, I'll pass that along.’ But she was 100% right. Mark was incredible from day one.
Of course, it’s hard to predict how far a show will really go, especially one that is the spinoff of an already successful show. And NCIS struggled during its early years, so you couldn’t really tell just how long it was going to last. Obviously, McGill’s wife turned out to be right, and I am so thankful that she was. I can’t imagine NCIS without Harmon as Gibbs, and he’s still such a big part of the franchise, so much so that he’s returning for NCIS: Origins’ upcoming third season.
There was no way of knowing just how much of a success NCIS would turn into, and I’m sure even McGill’s wife couldn’t have predicted 24 seasons and seven spinoffs by 2026. There are a lot of pieces of the puzzle that have made it successful, between the cast and the storylines, but you can’t argue that Harmon was definitely a big part of that, at least during the first half of the run.
Meanwhile, McGill’s wife may have predicted NCIS’ success because of Harmon, but Harmon admitted to being shocked that NCIS is still on the air. It did not do well when it was first starting out, struggling with ratings and trying to really find its footing. But knowing that it’s doing as well it is today is pretty remarkable. After over two decades, the NCIS franchise remains one of the most successful television franchises ever, and it doesn’t seem to be dying any time soon.
During the fall TV season, fans will be getting three NCIS shows, including Season 3 of NCIS: Origins, which will see Harmon reprising his role as Gibbs for all 10 episodes. Additional details about his appearance should be revealed in the coming weeks, but fans can watch the first two seasons of the prequel and all seasons of NCIS with a Paramount+ subscription.
