Mr. Klugman became a household name with his comic role in “The Odd Couple,” for which he received two Emmys during the show’s run on ABC from 1970 to 1975.
The series was adapted from a 1965 Neil Simon comedy about mismatched New York oddballs: a compulsively tidy photographer named Felix Unger who rooms with his best friend and fellow divorced man, an unkempt sportswriter named Oscar Madison. The play was a Broadway hit with Art Carney as Felix and Walter Matthau as Oscar. Matthau and Jack Lemmon co-starred in a 1968 film version.
Mr. Klugman stepped in as a replacement for Matthau on Broadway soon after the play opened. He was signed to play the role of Oscar in the television series, with Tony Randall cast as Felix.
The show was taped before a live audience, and the use of a laugh track was forbidden. If the crowd didn’t react to the jokes, the actors would ad-lib scenes until they found something the audience liked. When the show was edited, only the funniest takes were used.
Mr. Klugman won the first of his three Emmy Awards in 1964 for “The Defenders,” a courtroom drama. He played an actor whose old membership in a Communist-front organization had ugly repercussions during the Hollywood blacklist of the 1950s.
Before turning to television, Mr. Klugman was an established character actor in films, with roles in Sidney Lumet’s courtroom drama “12 Angry Men” (1957) and Blake Edwards’s “Days of Wine and Roses” (1962), in which he played an alcoholic. He also appeared in “Goodbye, Columbus” (1969) as the father of a spoiled young woman played by Ali MacGraw.
In 1976, Mr. Klugman returned to television in “Quincy, M.E.,” as a medical examiner in the Los Angeles County coroner’s office who used forensic science to get to the bottom of suspicious deaths. “Quincy” aired on NBC until 1983 and netted Mr. Klugman four Emmy nominations for lead actor in a dramatic series. He described “Quincy” as a precursor to later crime-scene investigation shows, which he said “just took what we did and made it bloodier and sexier.”
Jacob Joachim Klugman was born April 27, 1922, in South Philadelphia to an impoverished Jewish family. He was in his teens when his father, a house painter, died. His mother became a hat maker to support her six children.
Mr. Klugman said he was initially drawn to acting after watching child actor Jackie Cooper in the tear-jerking boxing drama “The Champ” (1931). He later said he did not pursue acting seriously because he thought actors “had to be born to a certain station in life.”
Mr. Klugman said he got into acting after he returned from Army service during World War II and acquired serious gambling debts.