In January 2012, he gained his first world championship title, when Grégory Baugé's results were nullified after a backdated 12-month ban for missing a drugs test, and the Union Cycliste Internationale (UCI) promoted Kenny to the gold medal. At the 2012 Summer Olympics in London, he won gold medals in both the team sprint and the individual sprint, beating Baugé in the final. At the 2016 Summer Olympics Kenny again won in the Team Sprint and the Individual Sprint, and also won the Keirin. In the 2020 Summer Olympics he won the Keirin again.