What Is Mark Harmon Doing Now 2025. Almost three after leaving ncis, news broke that harmon — who played ncis supervisory special agent leroy jethro gibbs from season 1 to season 19 — would be. Mark harmon appears in ‘ncis’ | courtesy of cbs.

The movie will arrive in. Mark harmon left ncis viewers devastated last year when it was announced that after almost two decades as the naval drama’s lead, he was bowing out of the show.