The Oscar winner died at his home in Connecticut with Elaine Taylor, his wife and best friend of 53 years, by his side, his manager confirmed to ABC News.
"Chris was an extraordinary man who deeply loved and respected his profession with great old fashion manners, self-deprecating humor and the music of words. He was a national treasure who deeply relished his Canadian roots. Through his art and humanity, he touched all of our hearts and his legendary life will endure for all generations to come," Lou Pitt, his longtime friend and manager of 46 years, said in a statement.
Plummer, who began his career on stage, made his film debut in 1958's "Stage Struck" and went on to a successful movie career that spanned more than six decades. He starred in a vast variety of films, including "The Return of the Pink Panther," "Murder by Decree," "Star Trek VI: The Undiscovered Country," "A Beautiful Mind," "Up," "The Imaginarium of Doctor Parnassus," "All the Money in the World," "The Girl with the Dragon Tattoo" and "Knives Out."
He earned his first Oscar nomination in 2010 for playing Leo Tolstoy in "The Last Station." He told Canadian television just before the Oscar broadcast, "Well, I said it's about time! I mean, I'm 80 years old, for God's sake. Have mercy." He lost that year to Christoph Waltz.
Two years later, at 82, he won the Academy Award for best supporting actor in "Beginners."
Accepting the award, he famously quipped, "You're only two years older than me, darling. Where have you been all my life?"
In addition to his Oscar, Plummer won two Emmy Awards, two Tony Awards, a Golden Globe Award, a SAG Award and a BAFTA Award.
But Plummer remained best known to film audiences as the patriarch of the singing von Trapp family, starring alongside Julie Andrews in the 1965 hit musical "The Sound of Music."
"I'm still remembered for it, much to my chagrin -- only because I've done so much more serious and interesting work. But at least it got me some of the best tables in restaurants all over the world," he told McGill University graduates in 2006.
Plummer was born in Toronto, the only child of Isabella Mary and John Orme Plummer. His father was secretary to the dean of sciences at McGill University. His mother was the granddaughter of Canadian Prime Minister Sir John Abbott.
Shortly after his birth, Plummer's parents divorced and he was brought up in his mother's family home in Senneville, Quebec, outside Montreal. At Montreal High School, he took on his first dramatic role as Mr. Darcy in "Pride and Prejudice." His performance caught the attention of Herbert Whittaker, a theatre critic and stage director for the Montreal Repertory Theatre, who cast Plummer at age 18 as Oedipus in Cocteau's "The Infernal Machine."
That led to an apprenticeship with the Canadian Repertory Company, followed by roles in New York and London. Even after becoming a successful movie actor, Plummer continued performing on stage.
Plummer was married three times. His first, to Tony Award-winning actress Tammy Grimes, produced a daughter, the actress Amanda Plummer. He is survived by his daughter and his third wife, Taylor, a British dancer and actress.