Born in St. Louis, Missouri, Garagiola grew up on Elizabeth Avenue in an Italian-American neighborhood in the west part of the city known as The Hill, just across the street from his childhood friend and competitor, Yogi Berra who was nine months older.
As teenagers in the early 1940s, almost all pro scouts rated Garagiola as the better baseball prospect, although Berra had a Hall of Fame career, and Garagiola always respected Berra's ability.