Antonovich was born in Los Angeles, California, and attended Thomas Alva Edison Junior High, where one of his classmates was Henry Waxman. He graduated from John Marshall High School and enlisted in the United States Army Reserve in 1957. A member of Sigma Nu fraternity, Antonovich graduated from California State University, Los Angeles in 1963 with a bachelor's degree and a master's degree in 1966. Antonovich taught in the Los Angeles Unified School District and later at Pepperdine University.
