Ronald James "Dio" Padavona was born in Portsmouth, New Hampshire, to Italian-American parents from Cortland, New York. His family moved to Portsmouth from Cortland as part of his father's service in the U.S. Army during World War II, and they resided there for only a short time before returning to Cortland. Padavona listened to a great deal of opera while growing up, and was influenced vocally by American tenor Mario Lanza. His first formal musical training began at age 5, learning to play the trumpet. Padavona participated in his high school's band program and was one of the youngest members selected to play in the school's official dance band. It was also during high school that Padavona formed his first rock-n-roll group, The Vegas Kings, which would later be named Ronnie and the Rumblers and then Ronnie and the Red Caps. Though Padavona began his rock-n-roll career on trumpet, he added singing to his skill set and also assumed bass guitar duties for the groups.