Mark Harmon Leads Heartfelt Tributes to NCIS and The Man From U.N.C.L.E. Legend David McCallum – You Won’t Believe the Emotional Farewells

Mark Harmon has paid tribute to his longtime NCIS co-star David McCallum, who passed away at the age of 90. McCallum, who played the beloved pathologist Dr. Donald “Ducky” Mallard on the crime drama, died peacefully on Monday, September 25, in New York City from natural causes. His passing has sparked an outpouring of grief and fond remembrances from the entertainment world.

Harmon, who portrayed the lead character Jethro Gibbs on NCIS for 18 years until his surprising exit, expressed his deep admiration and respect for McCallum in a statement shared with TVLine. “David lived a great, full, long life. I was in awe when I first met him, and all of us on the show were honored to have worked alongside him. My condolences go out to Katherine and his family,” said the 72-year-old actor.

Brian Dietzen, another NCIS star who often shared scenes with McCallum, also honored his late co-star with a heartfelt tribute on Instagram. “A life well lived. David McCallum was a mentor, a great scene partner, a wonderful father and husband, and he was my dear friend,” Dietzen wrote. He recalled meeting McCallum on his first day at NCIS and how their initial on-screen chemistry led to many more shared scenes and a deep, enduring friendship.

Dietzen praised McCallum for his quick wit, generosity, and his habit of uplifting his co-stars. “The friendship and respect people saw between Ducky and Jimmy over the years mirrored the relationship we’d developed off camera,” he shared. “Whether it was going on field trips for character research, attending charity events, or catching some golf together, he was always up for an adventure. The guy could do anything.”

Reflecting on McCallum’s remarkable life and career, Dietzen added, “He lived to be 90 years old, was a part of multiple hit TV shows, movies, Broadway shows, and wrote a couple of novels, all while raising a loving family. Thank you, David. Love you, my friend. I’ll miss you. Sending all my love to the McCallum family today.”

NCIS executive producers Steven D. Binder and David North also shared their thoughts, paying tribute to McCallum’s legacy. “For over 20 years, David McCallum endeared himself to audiences around the world playing the wise, quirky, and sometimes enigmatic Dr. Donald ‘Ducky’ Mallard,” they said. “But as much as his fans may have loved him, those who worked side by side with David loved him that much more.”