Referred to as "the King of Character Actors", Durning began his career in 1951. While working as an usher in a burlesque joint, he was hired to replace a drunken actor onstage. Subsequently, he performed in some 50 stock company productions and in various off-Broadway plays. He attracted the attention of Joseph Papp. Beginning in 1961, he appeared in 35 plays as part of the New York Shakespeare Festival. "That time in my life was my best time," Durning told Pittsburgh's Post Gazette in 2001. "I had no money at all, and he (Joseph Papp) didn't pay much. You were getting a salary for performance plus a rehearsal salary. We would do three plays in Central Park for the summer. And then you'd do three to six plays every year down on Lafayette Street -- new plays by new writers: Sam Shepard, David Mamet, David Rabe, John Ford Noonan, Jason Miller".