Mark Harmon to Make Guest Appearance as Gibbs on NCIS: Origins 4 Years After Exit from Franchise

The veteran actor, 74, will be guest starring in the first-ever NCIS and NCIS: Origins crossover event on Tuesday, Nov. 11. The actor, who played Leroy Jethro Gibbs for 18 seasons on the original series before exiting in 2021, will make his first on-camera appearance since his cameo in the prequel’s debut in 2024.

“In the crossover event airing on Veterans Day, younger Gibbs (Austin Stowell) and team investigate the small-town death of a naval officer in the ‘90s on NCIS: Origins – a case that’s unexpectedly re-opened in the present day on NCIS,” the official synopsis reads. “The decades-spanning mystery finds the air order for the series switching for one night only.”