Austin was born in New York City. Beginning a career as a child actor at the age of seven, he is the son of Giny Rodriquez Toranzo and Joe Szymanski. His middle initial, "T", is taken from his mother's maiden name. His mother is of Puerto Rican, Argentine and Spanish, descent, and his father is of Polish, Irish, and English descent. Austin embraces his Puerto Rican heritage, though he admits not being fluent in Spanish. He has one younger sister, Ava.