Stu Erwin began acting in college in the 1920s, having first appeared on stage. He broke into films in 1928 in Mother Knows Best. In 1934, he was cast as Joe Palooka in the film Palooka. In 1936, he was cast in Pigskin Parade, for which he was nominated for the Academy Award for Best Supporting Actor. In 1940, he played Howie Newsome, the dairy delivery vendor, in the film adaptation Our Town, based on the Thornton Wilder play. In Walt Disney's Bambi, Erwin performed the voice of a tree squirrel.