‘NCIS’ Mark Harmon Supports Recently Widowed Wife of Co-star David McCallum in Touching Tribute

• "NCIS" star David McCallum has died from natural causes aged 90.
• McCallum's co-star on "NCIS," Mark Harmon, has shared his tribute to the actor.
• Tributes for McCallum have also poured in from his other friends and co-stars.

David McCallum died on September 25, 2023, of natural causes at the age of 90. McCallum passed away at New York Presbyterian Hospital surrounded by family. His death comes only a week after he entered his 90s.

McCallum was an actor known for his role as Donald "Ducky" Mallard, a Chief Medical Examiner on the hit series "NCIS." He also starred in "The Man from U.N.C.L.E," a role that earned him an Emmy nomination.

McCallum has left behind his wife of 56 years, Katherine McCallum. He is also survived by his four kids, Paul McCallum, Valentine McCallum, Peter McCallum, and Sophie McCallum. McCallum lost one of his sons, Jason McCallum, in 1989.

The father of five has also left behind his eight grandchildren, Whit McCallum, Julia McCallum, George McCallum, Luca de Sanctis, Alessandro de Sanctis, Stella McCallum, Iain de Sanctis, and Gavin McCallum.

Several of McCallum's friends and co-stars have sent their condolences to the actor's family as they mourn their loving and kind husband, father, and grandfather. McCallum's longtime "NCIS" star, Mark Harmon, sent his tribute.

Harmon's Tribute to McCallum

Harmon issued a statement that celebrated the long, full, and great life McCallum lived. The actor said he was in awe when he met McCallum and that he and his co-stars were glad to have made a mark beside him. "My condolences go out to Katherine and his family," Harmon wrote.

Harmon was born in Pennsylvania, US, while McCallum was born in Glasgow, UK. Harmon, a former Marine, and McCallum, a charming, talkative, and intuitive person, crossed paths in 2003 and became good friends.

The "NCIS" team has also shared their tribute on X, noting that McCallum's "legacy will forever live on" via his family and the characters he played on-screen."

When Harmon met McCallum, the actor told his more experienced counterpart he couldn't believe he was shaking McCallum's hand. The two met during the shooting of the 2003 "JAG" episode "Ice Queen," which acted as the back-door pilot for "NCIS."

The pair's friendship in real life extended on-screen in "NCIS," where they solved countless cases together and supported each other during tragic occasions such as kidnappings, plagues, and deaths of colleagues.

Now, following the passing of his friend, Harmon has shared his condolences to McCallum's family and friends in mourning. Other friends and colleagues of McCallum have also shared their tributes after the actor's death.

Other Tributes from McCallum's Friends and Co-Stars

Brian Kelly Dietzen, who played Dr. Jimmy Palmer on "NCIS," has described McCallum in his tribute as a wonderful father and husband. Dietzen, who shared his tribute on Instagram, called McCallum a "screen legend," "dear friend," and "mentor."

McCallum's co-star Wilmer Eduardo Valderrama, who played Special Agent Nick Torres on "NCIS," has also celebrated his friend upon his passing. Valderrama said on Instagram that it was an immense honor for him to share a screen with a professional like McCallum.

Actress Emily Wickersham, who was Special Agent Eleanor Bishop on "NCIS," also honored McCallum on her Instagram story by saying the actor was a "professional and true legend" who will be missed.

Lauren Holly, who starred as Special Agent and Director Jenny Shepherd on "NCIS," said in her tribute on X that McCallum was "the kindest man." Jon Cryer, the captain of the Navy on "NCIS" Dr. Cyril Taft, also noted in his tribute on X that McCallum was a "witty, joyful, and wonderful" actor.

The "NCIS" team has also shared their tribute on X, noting that McCallum's "legacy will forever live on" via his family and the characters he played on screen. Michael Weatherly, who played Special Agent Anthony DiNozzo on "NCIS," celebrated McCallum as a "fantastic" and "authentic man."

"NCIS" executive producers Steven D. Binder and David North also shared their tribute, calling McCallum a "scholar and a gentleman." McCallum has died, but his impact is evident through all the tributes shared so far. The actor will be immensely missed by his family, friends, and co-stars.