Zoe Caldwell, one of the most acclaimed stage performers of her generation, who won four Tony Awards for playing complex female characters ranging from Medea in classical Greek tragedy to the powerful yet vulnerable Maria Callas in “Master Class,” died Feb. 16 at her home in Pound Ridge, N.Y. She was 86.

She had complications from Parkinson’s disease, said her son Charlie Whitehead.

Ms. Caldwell, whose first name was pronounced with one syllable, “Zoh,” was born in Australia and was acting professionally at age 9. She was a veteran classical performer — appearing in works by William Shakespeare, George Bernard Shaw and Anton Chekhov — before making her Broadway debut in 1965 as a disturbed nun in John Whiting’s “The Devils.”

A year later, Ms. Caldwell was cast in Tennessee Williams’s “Slapstick Tragedy,” which ran for less than a week. Still, her performance as a Southern society columnist earned her the Tony Award for best supporting actress.

In 1968, she appeared in the title role of “The Prime of Miss Jean Brodie,” portraying a charismatic but domineering teacher at a Scottish girls’ school in the 1930s. At first, the play’s producer, Robert Whitehead, did not think the diminutive Ms. Caldwell was right for the role, but he was persuaded by Jay Presson Allen, who had adapted the play from Muriel Spark’s novel.

“I like her so much,” Ms. Caldwell said at the time, “that every night I strip down stark naked and start becoming Brodie from scratch — I pull at my hair here, twist it a bit there, get the feel of her shoes. I couldn’t play any part I didn’t like.”

Her performance inspired rapturous reviews.

“What she is up to is extraordinary,” New York Times theater critic Walter Kerr wrote. “Miss Caldwell is not precisely acting a character; she is inventing, in clear amber light, a mobile nightmare — intense, wildly proportioned, antic and slippery, chilling.”

Ms. Caldwell received the Tony Award for best actress in a play, and she and Whitehead were married during the play’s almost year-long Broadway run.

Over the next few years, Ms. Caldwell appeared in an off-Broadway play about the life of French writer Colette and turned to directing, including several plays by Shakespeare and a 1977 Broadway comedy, “An Almost Perfect Person,” starring Colleen Dewhurst as a congressional candidate.

She continued to act periodically and, after several failed plays, triumphed again on Broadway in “Medea,” by classical Greek dramatist Euripides and directed by her husband. Playing the vengeful, amoral Medea, Ms. Caldwell imbued the character with a raw sexuality that seemed almost shocking.

“People talk about the things I do with my body,” she told the Times. “We studied so many Greek paintings and sculptures, and that’s how it evolved.”

She won a third Tony Award for the role.

Early in her career, Ms. Caldwell had met Terrence McNally, a young dramatist who promised to write a play for her. That play turned out to be “Master Class,” McNally’s depiction of the opera star Callas teaching at the Juilliard School after her voice has deserted her.

Ms. Caldwell learned everything she could about Callas and mastered her lilting Greek-Italian accent. She found an aching vulnerability at the heart of the character. “She lets you in on her soul,” she said of Callas, “and her soul is molded by art.”

Ms. Caldwell even interviewed one of Callas’s former students to prepare for the role: “She said, ‘And then, of course, there was the way she strode.’ I said, ‘Strode? Show me! Stride!’ ”

In the play, Ms. Caldwell, as Callas, cajoles, criticizes and confides in her students.

“You expect people to remember you if you don’t have a look?” she asks. “You. Yes, you, and don’t take this personally. You don’t have a look. You look very nice, I’m sure you are . . . but you don’t have a look. Get one. As quickly as possible.”

In one scene with a character played by Audra McDonald, Ms. Caldwell exhorts her protegee to greater musical heights, telling her, “This isn’t just an opera. This is your life.”

“Master Class” premiered on Broadway in 1995 and won Tonys for best play, best supporting actress (McDonald) and best actress, for Ms. Caldwell.

Associated Press theater critic Michael Kuchwara called her “an incandescent actress giving the performance of her career . . . ‘Master Class’ tops them all.”

Zoe Ada Caldwell was born Sept. 14, 1933, in Melbourne. Her father was a plumber, her mother a singer and dancer who encouraged her daughter’s theatrical interests.

“When I was a little girl in Australia, my parents took me to everything in the theater,” she told the Los Angeles Times. “We didn’t have any money, so we’d have to go in what they called the Gods, the balcony.”

She often appeared on the radio in her early years, including an interview show with celebrities when she was 12. She took classic roles at a young age and by her early 20s was in London, appearing in Shakespearean plays alongside such performers as Paul Robeson, Charles Laughton, Laurence Olivier and Dame Edith Evans.

In 1959, she was in a production of “Coriolanus” with Albert Finney; in her 2001 memoir, “I Will Be Cleopatra,” Ms. Caldwell admitted that she was named as a co-respondent in Finney’s first divorce.

Ms. Caldwell was married to Whitehead, who produced and directed several of her plays, for 34 years until his death in 2002. Survivors include two sons and two grandsons.

Ms. Caldwell acted in a few films, including Woody Allen’s “The Purple Rose of Cairo” (1985), “Birth” (2004), opposite Nicole Kidman and Lauren Bacall, and “Extremely Loud & Incredibly Close” (2011), starring Tom Hanks, but she much preferred the immersion of acting in the theater.

When she took on the role of Lillian Hellman in William Luce’s 1986 one-woman play about the dramatist, Ms. Caldwell even took up smoking again, to inhabit her character more fully.

“The business of acting is sharing an experience,” she once told the Boston Globe. “Television and movies tend to cut off the element of sharing. Images flicker across the screen. Everything is mechanical. Everything is dead. Actors on the stage are alive. The audience is alive.”