[3] Entering show business as a stand-in for Jackie Gleason in The Honeymooners in 1955–56 and as a part-time writer for Steve Allen in the 1950s, he was discovered by Mel Brooks, who cast him in The Producers.

In 1979, he was cast as the title character in Norman Lear's final TV series concept, McGurk: A Dog's Life.

In 1993, Martin played the recurring role of "Pete Peters" on the Don Rickles sitcom Daddy Dearest.

In 1975, Martin originated the role of Amos Hart in the Broadway musical Chicago, in which he introduced the song "Mr. Cellophane".

He appeared in an episode of Full House as Ranger Roy, the host of a popular kids' TV show.

In 1981, he portrayed Ralph Marolla, father of Liza Minnelli's character in the film Arthur and the following year appeared on Barney Miller in the episode "Obituary".

Martin died of bladder cancer on March 21, 2005, in Studio City, Los Angeles, California, at age 82.