Tributes poured in from Hollywood. Actor and director Rob Reiner said on Twitter that Douglas "will always be an icon in the pantheon of Hollywood. He put himself on the line to break the blacklist."
Mitzi Gaynor, who appeared with Douglas in the 1963 movie "For Love or Money," said the film would "always hold a special place in my heart."
"Thank you for so generously sharing your amazing talent with all of us," Gaynor tweeted.
Danny DeVito called him an "inspirational Scallywag," while Ed Asner tweeted "I will always be in your awe."
A stroke in 1996 at age 80 left Douglas with slurred speech and damaged facial nerves. But two weeks later he showed his spirit by attending the Academy Awards ceremony to receive a Lifetime Achievement Award. He also continued to take small acting roles through 2008 but said the stroke left him suicidal.
"Humor saved me," Douglas told Parade magazine in 2014. "At first, I thought my life was at an end. But when I put the gun in my mouth, it hit a tooth. Ow! And that struck me funny. A toothache was stopping me from committing suicide?"
In one of his last public appearances, Douglas was frail and barely audible in a wheelchair as he helped daughter-in-law Catherine Zeta-Jones present the Oscar for best screenplay in January 2018. In November of that year he joined his son Michael as the younger Douglas was honored with a star on the Hollywood Walk of Fame.
Douglas had a distinctive chin, razor-sharp cheekbones and a jutting jaw - looks that he passed along to Michael - and that made him a natural for playing all manner of rugged characters.
He also had a demanding nature that earned him a reputation in his prime as the actor who directed directors. Long-time friend and sometime co-star Burt Lancaster loved to introduce him by saying, "Kirk would be the first to admit he is a difficult person. (Pause) I would be the second."
"I make my own way," Douglas once told an interviewer.
"Nobody's my boss. Nobody's ever been my boss ... I've been a maverick."
