Mr. Roberts appeared in dozens of films and Broadway shows but was best known as the unflappable counterpoint to Allen’s tightly wound characters.

Roberts appeared on Broadway in the 1966 Woody Allen comedy "Don't Drink the Water," repeating his role in the film version, and in Allen's "Play It Again, Sam" (1969), for which he also made the movie.

He had an acclaimed Broadway career in musicals and comedies, but moviegoers knew him mostly as the self-assured, easygoing friend of Mr. Allen’s insecure heroes.