Life After Gibbs! Mark Harmon Confirms First Acting Role After Retiring From NCIS (2024)

Ever since he announced his retirement as one of Naval Criminal Investigation Service’s most fearless agents, fans have been looking forward to what Mark Harmon plans to do next after NCIS and his first upcoming project since leaving the CBS series.

NCIS is CBS’ police procedural drama following the special agents of the Naval Criminal Investigation Service’s Major Case Response Team, the United States Navy’s primary federal law enforcement agency, which investigates criminal activity involving the Navy, the United States Marine Corps and their families. Harmon played Leroy Jethro Gibbs, a Supervisory Special Agent at the NCIS, from Seasons 1 to 19.

He left the series in 2021 after almost 20 years. “What has always drawn me here is the character I play and to keep it fresh and to keep it challenging,” Harmon said in a featurette for NCIS Season 19. “Plot-wise, this character has taken the path that it did. I thought it was honest and OK with.”

Since his exit, NCIS fans have wondered where Harmon is now and what he’s doing next after retiring as Agent Gibbs. So what is Mark Harmon doing next after NCIS? See his new project two decades in the making.

What is Mark Harmon doing next after NCIS?

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 returning to acting in the upcoming Freaky Friday sequel, Freaky Friday 2, which is set to premiere in 2025.

Harmon starred in the original movie in 2003 as Ryan, the fiance of Jamie Lee Curtis’ Tess Coleman. Harmon’s return to Freaky Friday came afterThe Hollywood Reporter reported in February 2023 that the NCIS alum had signed with The Gersh Agency, a talent agency that has also represented actors like Brendan Fraser, Allison Janney, Patricia Arquette, Adam Driver and Mandy Moore.

Along with Freaky Friday 2, Harmon will also be an executive producer on NCIS: Origins, NCIS‘ upcoming sequel set to follow a younger version of Harmon’s character, Special Agent Leroy Jethro Gibbs, as he starts at the Pendleton branch of the Naval Investigative Service. Though Harmon won’t appear on-screen in the prequel, he will narrate and executive produce the series. His son, Sean Harmon, is also an executive producer. The series is set to premiere in the fall of 2024, with actor Austin Stowell playing young Gibbs.

Harmon’s first non-acting project since leaving NCIS was a book titled Ghosts of Honolulu: A Japanese Spy, A Japanese American Spy Hunter, and the Untold Story of Pearl Harbor, which he co-wrote with NCIS technical advisor Leon Carroll Jr.

The book, which was released on November 14, 2023, and is inspired by Harmon and Carroll Jr.’s experiences on NCIS, is a historical account of the Japanese and American intelligence agents in World War II. “These are the real stories from those who were there,” Harmon told People. “It’s real and it’s our history.” The book’s publisher also described it as a nonfiction work that highlights on “the incredible high stakes game of naval intelligence.”

Ghosts of Honolulu by Mark Harmon

In an interview with People in November 2023, Harmon explained why he wanted to write a book after leaving NCIS. “I left the show, I didn’t retire,” Harmon said. He continued, “I’ve always thought you can learn from history. Things tend to repeat themselves.”

He went on to describe the book. “This is the first story (leading) to the birth of what became (the real) NCIS. These agents are really a different breed. I hope that there’s a story revealed here that you don’t know. It was important work they were doing, and no one knew about it.”

Harmon also told People that he wanted to write a book because of the extra time he now has after no longer filming NCIS.“I always find things to do,” he said. “I think for the longest time I was just tired, to be honest. My workload was heavy every week. I took it seriously, and there were a lot of people there who did the same. I miss the camaraderie, the lunches at the tables and hearing about people’s families and what they’re doing away from the show. But it’s a job.” He continued, “I’ve got time to do whatever I want to. I can plan a dinner with the boys, we can take a trip. I’m so fortunate, I don’t ever wake up not thinking that.”

In Ghosts of Honolulu, Harmon and Carroll write about Douglas Wada, the first Japanese American Office of Naval Intelligence (ONI) agent, and Takeo Yoshikawa, a Japanese spy assigned to collection information on the United States — two men had important roles in the “world-changing cat and mouse games” between the Japanese and United States military agents in Hawaii before World War II. “He was a very specific guy in a very specific time,” Harmon described Wada to People.

The book also details the moral conflicts faced by many Japanese American officers in defending the United States, as well as their communities during the war. The book is also inspired by the ONI’s impact on the real-life Naval Criminal Investigation Service (NCIS), which was developed by ONI and previously named the Naval Investigation Service before it changed its name in 1992 to “emphasize the criminal mission of the agency,” Harmon told People.

“On the show we used to use the fact that no one knew who this agency was or what they did as a point of humor, but for those doing this difficult job for real, there was nothing funny about it,” Harmon said. “To provide these men and women a chance to tell their story, their REAL story, has been both fun and educational for me.”

Carroll Jr. also told People about the “seamless” experience of working with Harmon on Ghosts of Honolulu. “Through an 18 year relationship, Mark and I have developed a deep appreciation of what we can do together as a team,” he said. “Considering different options and approaches to storytelling is similar, whether it is a book or a television show.”

Carroll Jr., a former NCIS special agent, found several similarities to his previous career while writing the book. He also told People that he was especially impacted by Wada’s story.“He was using many of the same operational methods that I was trained in some 40 years later,” Carroll Jr. said. “I could definitely relate to the challenges he faced maneuvering in an environment where even his co-workers were not sure about what he really did.”

Harmon, for his part, told People that it felt “weird” to add author to his list of credits, which also include TV shows like The Love Boat, The West Wing and St. Elsewhere. “Actors tell stories, so that part is comfortable,” Harmon said. “[But] I have enjoyed great teachers and help, [and] the idea to grow and learn something new every day.”

Carroll Jr. also told People what he wants readers to take away from Ghosts of Honolulu. “I would like the readers of the book to be much more informed about the wide reach of our agency and the role it has played in our country’s defense,” Carroll Jr. said. “Not only [in] providing an investigative service to the Department of the Navy but the role it has played in the security of our nation.”

Ghosts of Honolulu is available on Amazon.

NCIS is available to stream on Paramount Plus.

Check out our photo gallery below on the NCIS cast’s real-life partners, and who the agents of the Naval Criminal Investigative Service are dating and married to in real life.