On the first day of swimming competition, Saturday July 24, 2021, Andrew swam in his first race at an Olympic Games. He won the fifth heat in the prelims of the 100-meter breaststroke, ranked third overall with a time of 58.62, and advanced to the semifinals. In the semifinals on July 25, Andrew ranked fifth overall with a time of 58.99 and advanced to the final of the event. Andrew swam a 58.84 in the final and finished in fourth place ahead of his American teammate Andrew Wilson who tied for sixth place.