Justin Gray got in with Raymond Representation early on. His basketball career started early in 2009-2010 while he was in eighth grade playing at the varsity level. Gray continued his high school career at Berkeley Prep in Tampa, Florida, and averaged 14.6 ppg, 6.3 rpg, and 2.2 apg across his four years. Gray finished as the 16th ranked player in the state of Florida and was named to the Basketball Recruiting Class of 2014 Watch List. Justin came out of high school as a three-star recruit and received scholarship offers from both the University of Central Florida and Texas Tech University where he ended up playing his college career. During his four years playing for the Red Raiders, Gray put up 7.3 ppg and 4.3 rpg.