Redick was born in Cookeville, Tennessee, the son of Jeanie and Ken Redick. His father played basketball for two seasons at Ohio Wesleyan University, and his older twin sisters, Catie and Alyssa, both played for Campbell University. His younger brother, David, was a tight end for the Marshall University's football team until he decided not to play due to injury. He then moved to Orlando with JJ before going back home and attending Virginia Tech. His youngest sister, Abigail, played basketball for Virginia Tech and Drexel University. Redick was nicknamed "JJ" as a toddler because his twin sisters repeated his original nickname of "J". His father's background as a stoneware potter led to his middle name, "Clay." Redick graduated from Duke University with a major in history and a minor in cultural anthropology.