At Kentucky, Riley played under the legendary coach Adolph Rupp. From 1964 to 1967, he was a key player for the Wildcats, known for his tenacity and leadership on the court. Riley's college career reached its pinnacle in his senior year when he captained Kentucky to the 1966 NCAA championship game. Although the Wildcats lost to Texas Western (now the University of Texas at El Paso) in a historic match that broke racial barriers in college basketball, Riley's performance throughout the tournament solidified his reputation as a top-tier player.