Belinksy was born in New York City, to a Polish-American Catholic father and a Jewish mother. He grew up in Trenton, New Jersey. He became a "street rat" and one-time pool gambler. Belinsky was already getting in trouble while still in the minor leagues for partying at night. He pitched for several seasons in the Baltimore Orioles minor leagues. His career and life changed when the Angels picked him in a minor league draft for the 1962 season. 