William Bast was born and raised in Milwaukee, Wisconsin. After graduating from high school, he spent his first year as an undergraduate in pre-law at the University of Wisconsin, then transfered to UCLA in Los Angeles where he changed his study course to Theater Arts.
In 1950, he met and befriended another UCLA Theater Arts student, James Dean, with whom he shared living quarters while at UCLA. During the five years that followed, while living in Los Angeles and New York together, the two young men pursued their professional careers, Bast as a writer, Dean as an actor.
