He was born May 30, 1908, in San Francisco. He began collecting dialects and characterizations in his youth, first mastering a thick Yiddish borrowed from an old Jewish couple who ran a grocery store in his neighborhood. He added the sounds of Chinatown (in Portland, where his family had moved) to what was quickly becoming an act. By the time he finished high school, Blanc was an actor, doing occasional skits on local radio with his brother Henry.