John Stompanato, Jr. was born in Woodstock, Illinois. His father, John Sr., owned a barber shop. His mother, Carmela, was a seamstress. Both parents were born in Italy, but were married in Brooklyn. The family moved to Woodstock in 1916. Johnny was the youngest of four children and grew up with two older sisters, Grace and Teresa; and older brother, Carmine. Six days after John's birth, his mother died of peritonitis. Johnny's father soon remarried a woman named Verena Freitag.