Christopher Plummer, the prolific and versatile Canadian-born actor who rose to celebrity as the romantic lead in perhaps the most popular movie musical of all time, was critically lionized as among the pre-eminent Shakespeareans of the past century and won an Oscar, two Tonys and two Emmys, died on Friday at his home in Weston, Conn. He was 91.

His wife, Elaine Taylor, said the cause was a blow to the head as a result of a fall.

The scion of a once-lofty family whose status had dwindled by the time he was born, Mr. Plummer nonetheless displayed the outward aspects of privilege throughout his life. He had immense and myriad natural gifts: a leading man’s face and figure; a slightly aloof mien that betrayed supreme confidence, if not outright self-regard; an understated athletic grace; a sonorous (not to say plummy) speaking voice; and exquisite diction.

He also had charm and arrogance in equal measure, and a streak both bibulous and promiscuous, all of which he acknowledged in later life as his manner softened and his habits waned. In one notorious incident in 1971, he was replaced by Anthony Hopkins in the lead role of “Coriolanus” at the National Theater in London; according to the critic Kenneth Tynan, who at the time was the literary manager of the National, Mr. Plummer was dismissed in a vote by the cast for crude and outrageous behavior.

For years, until he came to share the widely held opinion of his best-known film — the beloved 1965 musical “The Sound of Music,” in which he starred as the Austrian naval officer Georg von Trapp opposite Julie Andrews — as a pinnacle of warmhearted family entertainment, Mr. Plummer disparaged it as saccharine claptrap, famously referring to it as “S&M” or “The Sound of Mucus.”

“That sentimental stuff is the most difficult for me to play, especially because I’m trained vocally and physically for Shakespeare,” Mr. Plummer said in a People magazine interview in 1982. “To do a lousy part like von Trapp, you have to use every trick you know to fill the empty carcass of the role. That damn movie follows me around like an albatross.”

Mr. Plummer’s résumé, which stretched over seven decades, was at least colossal, if not nonpareil, encompassing acting opportunities from some of dramatic literature’s greatest works to some of commercial entertainment’s crassest exploitations. He embraced it all with uncanny grace, or at least professional relish, displaying a uniform ease in vanishing into personalities not his own — pious or menacing, benign or malevolent, stern or mellow — and a uniform delight in delivering lines written by Elizabethan geniuses and Hollywood hacks.

He played Hamlet, Macbeth, Richard III, Mark Antony and others of Shakespeare’s towering protagonists on prominent stages to consistent acclaim, and he starred in “Hamlet at Elsinore,” a critically praised 1964 television production, directed by Philip Saville and filmed at Kronborg Castle in Denmark, where (under the name Elsinore) the play is set.

But he also accepted roles in a fair share of clinkers, in which he made vivid sport of some hoary clichés — as the evil bigot hiding behind religiosity in “Skeletons” (1997), for example, one of his more than 40 television movies, or as the somber emperor of the galaxy who appears as a hologram in “Starcrash,” a 1978 rip-off of “Star Wars.”

One measure of his stature was his leading ladies, who included Glenda Jackson as Lady Macbeth and Zoe Caldwell as Cleopatra. And even setting Shakespeare aside, one measure of his range was a list of the well-known characters he played, fictional and non, on television and in the movies: Sherlock Holmes and Mike Wallace, John Barrymore and Leo Tolstoy, Aristotle and F. Lee Bailey, Franklin D. Roosevelt and Alfred Stieglitz, Rudyard Kipling and Cyrano de Bergerac.

‘Simply Stupendous’

Mr. Plummer’s television work began in the 1950s, during the heyday of live drama, and lasted half a century. He starred as the archbishop in the popular 1983 mini-series “The Thorn Birds,” appeared regularly as an industrialist in the 1990s action-adventure series “Counterstrike,” and won Emmy Awards — in 1977 for portraying a conniving banker in the mini-series “Arthur Hailey’s The Moneychangers,” and in 1994 for narrating “Madeline,” an animated series based on the children’s books.

In the movies, his performance in “The Sound of Music” as von Trapp, a severe widower and father whose heart is warmed and won by the woman he hires as a governess, propelled a parade of distinctive roles, more character turns than starring parts, across a formidable spectrum of genres. They included historical drama (“The Last Station,” about Tolstoy, and “The Day That Shook the World” about the onset of World War I); historical adventure (as Kipling in John Huston’s rollicking adaptation of “The Man Who Would Be King,” with Sean Connery and Michael Caine); romantic comedy (“Must Love Dogs,” with John Cusack and Diane Lane); political epic (“Syriana”); science fiction (as Chang, the Klingon general, in “Star Trek VI”); and crime farce (“The Return of the Pink Panther,” in which, opposite Peter Sellers’s inept Inspector Clouseau, he played a retiree version of the debonair jewel thief originally portrayed by David Niven).

Mr. Plummer won a belated Oscar in 2012 for the role of Hal, a man who enthusiastically comes out as gay after a decades-long marriage and the death of his wife, in the bittersweet father-son story “Beginners.”

“Simply stupendous,” Peter Travers of Rolling Stone wrote of that performance, in one of many prominent reviews that treated it as a triumphant valedictory. At 82, he was the oldest person ever to win an Academy Award in a competitive category.

“You’re only two years older than me, darling,” Mr. Plummer said, addressing the golden statuette during his acceptance speech. “Where have you been all my life?”

A dozen or more of his roles came after his 75th birthday, among them the thriller “The Girl With the Dragon Tattoo” (2011); “Barrymore” (2011), a screen version of the stage show for which he earned his second Tony Award in 1997 for his tour de force portrayal of the actor John Barrymore; the Rian Johnson whodunit “Knives Out” (2019); and the fact-based drama “The Last Full Measure” (2019), starring William Hurt.

In 2017 he starred as J. Paul Getty, the billionaire who refuses to pay a ransom for his kidnapped grandson, in the Ridley Scott movie “All the Money in the World,” a role he stepped into at the last minute to replace Kevin Spacey, who had been accused of sexual misconduct. His formidable performance, described as “so dominating, so magnetic and monstrous” by the New York Times critic Manohla Dargis, earned him an Oscar nomination.

“I’m not a superstar — thank God,” Mr. Plummer said in an interview with The Times in 1982. “Christ, to be a superstar must be extremely tiring and limiting.

“I prefer being half-recognized on the street and getting good tables in restaurants,” he added. “Unfortunately, the really good, smashing parts do not always come my way because they go to the first tier of superstars who are bankable.”

As accurate as that self-assessment was, it pertained only to the movies. Onstage, with a fierce intelligence, exemplary control of his body and voice, and a formidable command of language, Mr. Plummer had few equals.

“As T.S. Eliot measures his life with coffee spoons, so I measure mine by the plays I’ve been in,” he wrote in his expansive 2008 memoir, “In Spite of Myself.”

A Shakespearean Foremost

Mr. Plummer made notable Broadway appearances in works by Archibald MacLeish (the Devil-like Nickels in “J.B.” in 1958), Bertolt Brecht (the Hitler-like title role in “Arturo Ui” in 1963), Peter Shaffer (the Spanish conquistador Francisco Pizarro in “The Royal Hunt of the Sun” in 1965), Neil Simon (the Chekhov-like narrator in “The Good Doctor” in 1973) and Harold Pinter (“No Man’s Land,” opposite Jason Robards, in 1994).

He won a Tony in the title role of “Cyrano,” a 1973 musical version of Edmond Rostand’s “Cyrano de Bergerac,” and in 2007 he was nominated for a Tony for the Clarence Darrow-like role of Henry Drummond, opposite Brian Dennehy, in “Inherit the Wind,” his final Broadway appearance.

Even so, that was the second tier of his theatrical portfolio; he was first and foremost a Shakespearean, one who brought febrile intensity and fierce intellect to his preparation.

“I disagree with the theory that he is a man of indecision,” Mr. Plummer wrote about Hamlet in an essay for Playbill in 1964. “The truth is that he has made his mind up many times over, and it is only through his self-analytical precision and towering imagination that he finds himself living the deed long before he commits himself to its performance.”

In 1955, he played Mark Antony in “Julius Caesar” in the inaugural production of the American Shakespeare Festival Theater in Stratford, Conn. The next year he played the title role in “Henry V” at the Stratford Shakespearean Festival in Ontario — where he became a fixture — and was declared by Brooks Atkinson of The Times to be “a Shakespearean actor of the first rank.”

For more than a half century, through 2010 — when, at age 80, he appeared at the Stratford festival as Prospero in “The Tempest” — Mr. Plummer’s performances, including those in New York and in London, where he lived in the 1960s, were more often than not appreciated in extravagant terms.

“The performance of a lifetime,” Ben Brantley wrote in The Times of Mr. Plummer’s “King Lear,” which arrived on Broadway in 2004 after first being produced at the festival. “He delivers a Lear both deeply personal and universal: a distinctly individual man whose face becomes a mirror for every man’s mortality.”

Ms. Taylor, his wife, said that at his death Mr. Plummer had been preparing to appear as Lear on film for the first time, under the direction of Des McAnuff.

But it was his portrayal of Iago in a 1981 Connecticut production of “Othello,” which starred James Earl Jones in the title role and came to Broadway in 1982, that defined his reputation as a Shakespearean of profound depth, worthy of comparison to the likes of Laurence Olivier, Michael Redgrave and John Gielgud.

“He gives us evil so pure — and so bottomless — that it can induce tears,” Frank Rich wrote in The Times. “Our tears are not for the dastardly Iago, of course — that would be wrong. No, what Mr. Plummer does is make us weep for a civilization that can produce such a man and allow him to flower.”

The praise was amplified by the senior Times critic of the day, Walter Kerr, who wrote, “It is quite possibly the best single Shakespearean performance to have originated on this continent in our time.”

A Rebellious Boyhood

Arthur Christopher Orme Plummer was born in Toronto on Dec. 13, 1929. His parents separated around the time of his birth, and he did not meet his father, John Orme Plummer, until he was 17, when the elder Plummer came to see his son perform in a play.

“Our paths would cross once or twice again in our lifetimes and then no more,” Christopher Plummer wrote in his memoir.

Mr. Plummer grew up in Montreal with his mother — Isabella Mary Abbott Plummer, a granddaughter of a Canadian prime minister and a railroad president — and her extended family in what he described as a colony of fading social aristocracy, where bird-watching and tennis were frequent recreational pursuits and the after-dinner activity was reading aloud. It was a background, he once said, that “made me want to be bad and rough and find the secrets rather than the gates.”

Pampered, gifted and rebellious, he aspired early on to be a concert pianist, though in high school, where his classmates included the future jazzmen Oscar Peterson and Maynard Ferguson, he gravitated to their musical style and a life at night that included heavy drinking.

“How often as a mere teenager, tanked to the gills on cheap rye whiskey and Molson chasers, did I stagger home in the blinding cold,” he wrote in his memoir.

He gave up the idea of a musical career because, he said, “I realized acting came easier.” He performed in high school shows — including as Mr. Darcy in “Pride and Prejudice,” in which he received a favorable review from The Montreal Gazette that “instantly went to my head” — and made his professional debut at 16 at the Montreal Repertory Theater.

Joining a troupe in Ottawa, Mr. Plummer performed in dozens of low-budget productions and, in what amounted to an extended education, took on roles in radio theater for the Canadian Broadcasting Corporation and spent a season with a professional company in Bermuda. The actor Edward Everett Horton, who had appeared with the company, secured him a role in a touring production of “Nina,” a French comedy, and opportunities accrued quickly.

Mr. Plummer appeared in “Medea” in Paris with Judith Anderson and made his Broadway debut in “The Starcross Story,” a drama that opened and closed on one January night in 1954 in spite of the lure of its star, Eva Le Gallienne. He toured in “The Constant Wife” with Katharine Cornell (who nearly had him fired for showing up for a performance late and hung over), and in 1955 appeared in his first commercial hit, as Warwick in “The Lark,” Jean Anouilh’s drama about Joan of Arc, starring an ascendant Julie Harris.

His first feature-film role was as a playwright in “Stage Struck,” a 1958 drama about the New York theater world, directed by Sidney Lumet and starring Henry Fonda, Susan Strasberg and Herbert Marshall.

By the early 1960s, Mr. Plummer had become allied with the bad boys of the British acting world — Richard Burton, Albert Finney, Peter O’Toole — motivated, he once said, by the cantankerous rage against propriety exhibited in the work of John Osborne.

In his memoir, a dishy, rollicking account of a life lived sensually and energetically, he was not shy in detailing his amorous adventures, or his drinking with fellow actors. In a 1967 interview with the CBC, he acknowledged himself to be a drunk — “though not when I’m working, producers take note,” he said — and considered the question of why actors in general drink.

“The more you give to an audience, which is a tremendous amount that you give during a night if you care about your work, the more you spill out of yourself with either loathing or loving them and getting loathing and loving back,” he said. “It’s a tremendous letdown when the evening is over. You’ve given an awful lot of your own personality with just the reward of applause at the end, which is a marvelous reward but it isn’t quite enough to fill the rest of the night.”

In the same interview he noted that he’d given up trying to be liked. “I’m not a difficult type to get on with,” he said. “I’m only difficult when I’m impatient with people who don’t understand temperament has nothing to do with lack of professionalism.”

Mr. Plummer’s first two marriages, to the actress Tammy Grimes and a British journalist, Patricia Lewis, ended in divorce. In addition to Ms. Taylor, he is survived by his daughter with Ms. Grimes, the actress Amanda Plummer.

By both their accounts, Mr. Plummer and his daughter became friends after she became an adult, though they had rarely seen each other while she was growing up.

“I didn’t want anything to do with the upbringing of a child,” he told The Times in 1982. “I am really very bad at responsibility of any kind. Unless it’s my work, I’m hopeless.”

It was Ms. Taylor, Mr. Plummer acknowledged many times, who curtailed at last his liquid nights and general profligacy.

“My long-suffering wife Elaine,” he called her, in closing his Oscar acceptance speech, “who deserves the Nobel Peace Prize for coming to my rescue every day of my life.”

Alex Traub contributed reporting.