On 15 April 2016 Main was named as one of five Olympic debutants in a squad of eight swimmers to represent New Zealand at the 2016 Summer Olympics in Rio de Janeiro, Brazil, where he competed in both the 100m and 200m Backstroke events. Main won his men's 100m backstroke heat with a time of 53.99 seconds to qualify for the semifinals. He finished 15th overall in the semifinals with a time of 54.29 seconds, but did not progress to the final. In the men's 200m backstroke event Main qualified 15th fastest for the semifinals with a time of 1:57.51 however his time of 1:58.08 was not enough to take him through into the final.