Erwin passed away Dec. 29 of age-related causes at his Studio City, Calif., home, not far from the production lot where Seinfeld was filmed, his son told the Los Angeles Times.
Erwin enjoyed a long career in movies, theater and particularly television, taking dozens of roles on shows including Gunsmoke, The Twilight Zone, Perry Mason, The Golden Girls, Growing Pains, Who's the Boss? and My Name Is Earl.
But his role as Sid Fields in the 1993 Seinfeld episode "The Old Man" brought him the most acclaim, along with an Emmy nomination.
Erwin was also fondly remembered for his role as Arthur the bellman in the 1980 fantasy film Somewhere in Time, and frequently returned to the Grand Hotel on Mackinac Island, Mich., where the film was set, to celebrate with fans.
Born in Texas in 1914, Erwin studied acting at the Pasadena Playhouse and performed in stage productions around Los Angeles through the decades. He was also a self-taught cartoonist who saw his work published in The New Yorker, Playboy and Los Angeles magazine.