Alan Arkin, who won a Tony Award for his first lead role on Broadway, received an Academy Award nomination for his first feature film, and went on to have a long and diverse career as a character actor who specialized in comedy but was equally adept at drama, died on Thursday in San Marcos, Calif. He was 89.

His son Matthew Arkin said that Mr. Arkin, who had heart ailments, died at home.

Mr. Arkin was not quite a show-business neophyte when he was cast in the 1963 Broadway comedy “Enter Laughing,” Joseph Stein’s adaptation of Carl Reiner’s semi-autobiographical novel about a stage-struck boy from the Bronx. He had toured and recorded with the Tarriers, a folk music group, and he had appeared on Broadway with Second City, the celebrated improvisational comedy troupe. But he was still a relative unknown.

He didn’t stay unknown for long.

In a cast that included established professionals like Sylvia Sidney and Vivian Blaine, Mr. Arkin stole the show and won the hearts of the critics. “‘Enter Laughing’ is marvelously funny, and so is Alan Arkin in the principal role,” Howard Taubman wrote in The New York Times.

Mr. Arkin won a Tony. The show ran for a year and made him a star.

Reviewers were again enthusiastic, and Mr. Arkin again found himself in a hit show, when he returned to Broadway in 1964 as a woebegone misfit in Murray Schisgal’s absurdist farce “Luv,” staged by Mike Nichols and co-starring Eli Wallach and Anne Jackson. With two Broadway triumphs under his belt, it was a confident Mr. Arkin who moved from the stage to the screen in 1966.

“I never had any doubts about making it in movies,” he told The Daily News a year later. “I just knew I had to, because there was no alternative.”

A complete obituary will appear shortly.

Robert Berkvist, a former New York Times arts editor, died in January.