Young, who is of German and Irish descent, was raised in Denver, Colorado, growing up in the same Boulder neighborhood as actress Jessica Biel and American Idol Season 2 contestant Samantha Cohen. He is the fifth and last son of Jay Young, a retired minor-league baseball player, and Kay Whitney, a cosmetologist and member of the Mormon Church (although Young himself is not a member of the Mormon religion, but rather a non-denominational Christian). Young has four older brothers: Josh, Duff, Marc, and Ryan. He was named after his maternal great-grandfather, Asa, and after baseball player George Brett; he has been called Ace by his family since his childhood and did not know his legal name until he was six years old.

Young, who has been singing since the age of nine, attended voice lessons and performed at local shopping malls and recreation centers during his youth. He performed at various venues in Colorado and other western states, most notably at the Pepsi Center in Denver.