Scouting site 247Sports ranked Clarke as the best player in the state of Virginia, as well as the ninth-best shooting guard and 41st overall prospect in the this year's senior class.
Rivals and ESPN ranked Clarke the 59th and 63rd best small forward in this year's class, respectively.
Clarke told the Knoxville News Sentinel in early October that Tennessee had shown more interest in him than any other school.
"I'm a guy they really need, a great addition to their team," Clarke said. "Tennessee loves me."
He is the third commitment to coach Donnie Tyndall's 2015 class. Forward Admiral Schofield of Illinois and guard Shembari Phillips, ranked No. 15 in the state of Georgia by 247Sports, committed to the Volunteers in August and September.