David McCallum Dead at 90: Mark Harmon, Michael Weatherly & More NCIS Stars Pay Tribute

The NCIS cast is in mourning following the tragic news of David McCallum's death at 90.

Deadline reported that the Scottish actor died Monday morning of natural causes surrounded by family at New York Presbyterian Hospital.

"For over 20 years, David McCallum endeared himself to audiences around the world playing the wise, quirky, and sometimes enigmatic Dr. Donald 'Ducky' Mallard," said current NCIS exec producers Seven D. Binder and David North in a statement.

"But as much as his fans may have loved him, those who worked side by side with David loved him that much more."

"He was a scholar and a gentleman, always gracious, a consummate professional, and never one to pass up a joke."

"From day one, it was an honor to work with him, and he never let us down," the statement adds.

"He was, quite simply, a legend. He was also family and will be deeply missed."

Mark Harmon, who costarred with McCallum, shared a tribute with Deadline.

"David lived a great, full, long life," he told the outlet.

"I was in awe when I first met him and all of us on the show were honored to have toed a mark opposite him. My condolences go out to Katherine and his family."

Michael Weatherly, who portrayed the popular DiNozzo for 13 years, took to X, writing:

"David McCallum made every moment count, in life and on set. Let's raise a jug and celebrate a funny fantastic authentic man."

"I've only got 3 autographs. Connery, Tony Bennett and McCallum," Weatherly continued.

"I felt the same way as Steve McQueen in this picture from The Great Escape: Wow!"

"It's David McCallum! No one did it better."

"We were lucky to have him bring us Ducky."

"Let's send all the love in the world to his beautiful family. Rest In Peace David."

Pauley Perrette, who played Abby Sciuto, wrote:

"Oh David. What a life. What a legend. What a journey," she wrote in part.

"And your legacy Will always be The love you have for your family." You can see her full tribute below.

Scroll down for more tributes.

Emily Wickersham

"Had the pleasure of working with David for many years and he was the utmost professional and a true legend. I will miss you David. Sending all my love to your family."

Wilmer Valderrama

"David, what an immense honor it was to share the screen with you.

Your professionalism and ability to effortlessly take every one of us on a journey through your art will be felt forever. I will miss you my friend."

Brien Dietzen

"A life well lived. David McCallum was a mentor, a great scene partner, a wonderful father and husband, and he was my dear friend."

McCallum appeared in all 20 seasons of NCIS on CBS, with the network sharing the following statement:

"We are deeply saddened by the passing of David McCallum and privileged that CBS was his home for so many years."

"David was a gifted actor and author and beloved by many around the world," the statement continues.

"He led an incredible life, and his legacy will forever live on through his family and the countless hours on film and television that will never go away."

"We will miss his warmth and endearing sense of humor that lit up any room or soundstage he stepped onto, as well as the brilliant stories he often shared from a life well-lived."

"Our hearts go out to his wife Katherine and his entire family, and all those who knew and loved David."

McCallum is survived by his wife of 56 years, Katherine McCallum; his sons Paul McCallum, Valentine McCallum, and Peter McCallum; his daughter, Sophie McCallum; and his eight grandchildren: