Kevin Thomas Riley was a Starfleet officer serving aboard the USS Enterprise in the 2260s.
By 2266, Riley was serving as navigator aboard the Enterprise as a lieutenant. In that year, Riley was one of the first crewmembers to fall victim to an unusual disease which caused those affected to act out and lose their inhibitions. Under the disease's influence, Riley commandeered the ship's engineering section, and rerouted all command functions there, prohibiting the rest of the crew from controlling the ship. This posed a significant danger to the Enterprise, as it was locked in an unstable orbit of the planet Psi 2000, and in the process of spiraling down towards the surface. Proclaiming himself "Captain Kevin Thomas Riley," he deactivated the ship's engines and regaled the crew with repeated renditions of the song "I'll Take You Home Again, Kathleen." Eventually, Captain Kirk and crew were able to regain control of the ship, and institute a full-power restart of the engines, narrowly avoiding destruction of the Enterprise.