His son says Stang died of pneumonia Sunday at Newton-Wellesley Hospital in Massachusetts. He was 91.
The New York City native started his career on the radio as a teenager. He played alongside Milton Berle in the 1950s, starred as Frank Sinatra's sidekick in the 1955 movie "The Man with the Golden Arm," and was a member of the ensemble comedic cast of "It's a Mad, Mad, Mad, Mad World" in 1963.
He voiced the lead character in the 1960s cartoon "Top Cat," and continued comedy and drama roles into his 80s.
Stang, who had lived in the Boston suburb of Needham for the past decade, is survived by his wife of 60 years, JoAnne; son, David; and daughter, Deborah.