Ron Leibman, a stage actor who also appeared in dozens of films and television shows and won a Tony Award in 1993 for his portrayal of lawyer Roy Cohn in Tony Kushner’s play “Angels in America,” died Dec. 6 in New York. He was 82.

His agent, Robert Attermann, confirmed the death but gave no further details. A person who knew the actor, speaking on the condition of anonymity, said the cause was pneumonia.

In a lengthy career, Mr. Leibman played a huge variety of roles, both dramatic and comic. He appeared in numerous films including “Slaughterhouse-Five” (1972) and “Norma Rae” (1979), in which he played a union organizer opposite Sally Field, who won an Oscar for best actress for her performance as a factory worker who organizes a union.

Mr. Leibman won an Emmy Award in 1979 for the short-lived CBS series “Kaz,” which he created and starred in as Marvin Kazinsky, a onetime prison inmate who becomes a lawyer. He played a doctor in several episodes of “The Sopranos,” but he was perhaps best known on television for his role in the long-running sitcom “Friends,” where he played Leonard Green, the father of Rachel, the character played by Jennifer Aniston.

The crowning moment of Mr. Leibman’s career was his performance in “Angels in America” as Cohn, the firebrand lawyer who had been chief counsel to Sen. Joseph McCarthy (R-Wis.) in the 1950s. Cohn was a closeted homosexual who died of AIDS in 1986.

In the play, Cohn is facing disbarment at the same time he is dying of AIDS, which he refuses to admit. Mr. Leibman portrayed Cohn as “a demon of Shakespearean grandeur,” New York Times critic Frank Rich wrote after the first half of the two-part play “Millennium Approaches” opened on Broadway in 1993. Rich called Mr. Leibman’s performance “an alternately hilarious and terrifying mixture of chutzpah and megalomania, misguided brilliance and relentless cunning.”

When he accepted his Tony Award for best actor, Mr. Leibman noted that he had seen his first Broadway play when he was 3.

“I’ve been a professional actor for 35 years,” he said. “ ‘Angels in America’ is my 10th Broadway play, and this is my first Tony nomination. I hope you know in your hearts how deeply grateful I am to be here tonight.”

Thanking his wife, actress Jessica Walter, he quipped: “Maybe we can get an apartment with a washer-dryer now.”

Ronald Leibman was born Oct. 11, 1937, in New York. His father worked in the garment industry.

After studying at Ohio Wesleyan University, Mr. Leibman began working in theatrical troupes in the Midwest before returning to New York to study at the Actors Studio. He appeared in off-Broadway plays before making his Broadway debut in 1963 in a comedy, “Dear Me, the Sky Is Falling.”

In 1968, he was in the original cast of Joseph Heller’s antiwar comedy, “We Bombed in New Haven,” winning the first of two Drama Desk Awards. (The other was in 1970 for “Transfers.”) He played a prisoner of war in the 1972 film adaptation of Kurt Vonnegut’s novel “Slaughterhouse-Five.”

On Broadway, Mr. Leibman appeared again as Cohn in “Perestroika,” the second part of Kushner’s “Angels in America,” which opened in 1993. He received a Drama Desk nomination for best supporting actor.

Mr. Leibman also appeared on Broadway in two long-running Neil Simon comedies, “I Ought to Be in Pictures” (1980-81) and “Rumors” (1988-90). He played Shylock in a 1995 New York production of Shakespeare’s “The Merchant of Venice.”

In addition to “Friends” and “The Sopranos,” he had a recurring role in the TV crime series “Law & Order: Special Victims Unit.” More recently, he voiced a character named Ron Cadillac in the animated FX series “Archer,” about a secret agent.

Mr. Leibman’s first marriage, to actress Linda Lavin, ended in divorce.

Survivors include Walter, his wife since 1983; a stepdaughter; and a grandson.

CORRECTION: An earlier version of this obituary incorrectly referred to Mr. Leibman’s role in “Norma Rae.” He played a union organizer, not a lawyer. The story has been revised.