Robbie Coltrane, who played Hagrid in the Harry Potter films, died at the age of 72.

Robbie Coltrane, the veteran Scottish actor who acted in the "Harry Potter" films as the adored half-giant Rubeus Hagrid and in the popular British crime series "Cracker," died on Friday in Larbert, Scotland. He was 72.

Belinda Wright, his British agent, verified his death at a hospital. Mr. Coltrane's family had not specified a cause, although he had been "unwell for some years," according to Ms. Wright.

Mr. Coltrane's 40-year film and television career included roles as an antihero detective in "Cracker" (1993-96), a K.G.B. agent turned buddy to James Bond, and a mobster who disguises himself as a nun after betraying his fellow crooks in "Nuns on the Run" (1990).

But none of those jobs prepared Mr. Coltrane for the character of Hagrid, a fan favorite from the "Harry Potter" novels whose big-screen debut would meet the sky-high expectations of millions of young readers.

Mr. Coltrane was a convincing 8-foot-6 half-giant. He featured in all eight "Harry Potter" films, infusing the franchise with warmth even as he towered over the series' adolescent witches and wizards engaged in a battle against evil.

The first film, "Harry Potter and the Sorcerer's Stone," debuted in November 2001 and went on to generate more than $1 billion worldwide, adding to J.K. Rowling's already devoted global fan base.

Mr. Coltrane's 40-year agent, Ms. Wright, claimed the role was the reason he received a "torrent of fan letters every week for almost 20 years."

Mr. Coltrane, who was fiercely protective of his privacy, gave few interviews and could be tough with reporters. When he was hugged by a legion of young "Harry Potter" fans, he claimed he had to put his gruffness aside.

"With those huge doe-eyes, kids come up to you and say, 'Would you want to autograph my book?'" he told The Guardian in 2012. "It's also a big responsibility."

Anthony Robert McMillan was born on March 30, 1950, in Rutherglen, Scotland, just outside Glasgow. Ian Baxter McMillan, his father, was a doctor, and Jean Ross Howie, his mother, was a teacher.

He grew up on Glasgow's outskirts and attended Glasgow School of Art, where he studied sketching and painting but failed to put his thoughts on canvas.

"I wanted to paint like the painters who truly impacted me, who made me want to cry about humanity," he told the Scottish newspaper The Herald in 2014. “Titian. Rembrandt. But when I saw my diploma presentation, I was devastated because all of the things that were in my brain were not on the painting."

As his prospects as a painter diminished, he was encouraged by a theater teacher who told him he had acting skills after he performed in a production of Harold Pinter's one-act play "The Dumb Waiter," according to The Herald.

Mr. Coltrane established a more stable footing in London after adopting his stage name as an homage to the legendary jazz saxophonist John Coltrane. He performed as a stand-up comedian and actor, taking on theatrical roles as well as minor roles in television and film productions.

In the successful series "Cracker," he played Dr. Edward Fitzgerald, also known as Fitz, a chain-smoking criminal psychologist whose alcoholism mirrored Mr. Coltrane's own drinking problems. In 1994, 1995, and 1996, he won the BAFTA award for best TV actor for his performance.

A role in the James Bond films "GoldenEye" (1995) and "The World is Not Enough" (1999) as Valentin Zukovsky, a former K.G.B. agent turned Russian mafia lord, introduced Mr. Coltrane to a wider audience, notably in the United States.

Nothing, however, could compare to the global acclaim he achieved after being cast as Rubeus Hagrid in the "Harry Potter" series. Mr. Coltrane brought the popular character to life with his bushy beard and snarling voice.

Mr. Coltrane as Rubeus Hagrid in "Harry Potter and the Half-Blood Prince" (2009), with Jim Broadbent as Professor Horace Slughorn on the left and Daniel Radcliffe as Harry Potter on the right. Credit...Alex Bailey/Warner Brothers Pictures

Mr. Coltrane was remembered warmly by the young actors who grew up on the sets of the "Harry Potter" films as someone they could call on to boost their spirits with a joke or a word of encouragement.

Mr. Coltrane "used to keep us giggling continuously as youngsters," recalled Daniel Radcliffe, who played Harry Potter.

"I've very fond recollections of him keeping our spirits up on 'Prisoner of Azkaban,' when we were all hiding from the pouring rain for hours in Hagrid's hut and he was telling stories and cracking jokes to keep morale up," Mr. Radcliffe said in a statement.

Mr. Coltrane walked up to James Phelps, who portrayed Fred Weasley in the series, and said, "Enjoy it, you'll be amazing," when he was 14 years old and scared on his first day on the set.

Mr. Coltrane's children, Spencer and Alice, as well as his sister, Annie Rae, survive him.

Mr. Coltrane reminisced on the part that introduced him to a new generation of fans in the HBO Max retrospective "Harry Potter 20th Anniversary: Return to Hogwarts," which broadcast on Jan. 1.

"My children's generation will show them to their children," he added of the films' legacy. "So you may easily be seeing that in 50 years." Unfortunately, I won't be present, but Hagrid will."