Harper made his junior season debut on November 6, 2018 by recording his second career double-double, with 20 points and 13 assists, in a 101–58 win over South Alabama. On December 15, 2018, he scored a career-best 31 points in a 75–71 overtime win over UAB. At the end of the regular season, Harper earned second-team All-SEC honors from the Associated Press and conference coaches. In the NCAA tournament, Harper helped to lead the Tiger's to their first ever Final Four with a team high 26 points in the Tigers Elite Eight win against Kentucky.ge-basketball/game/_/gameId/401123390
