Larkin won a gold medal in the 200 meter backstroke and a silver medal in both the 50 meter and 100 meter backstroke at the 2014 Commonwealth Games in Glasgow, Scotland.
His personal best in long course events are 52.11 for the 100 meter backstroke[5] and 1:53.17 for the 200 meter backstroke,[6] both set at the Dubai world cup in November 2015.
In November 2015, Larkin broke the short courseworld record in the 200 meter backstroke, lowering it to 1:45.63.[7]
Despite only being three hundredths slower than his gold medal-winning time at the 2015 world championships, he missed out on a medal, finishing fourth in the final with a time of 52.43.
Larkin set a record as the first swimmer to win every backstroke event and also the most gold medals for a swimmer at a single Commonwealth Games event. Five gold medals included 50 meter, 100 meter and 200 meter backstroke, as well as the 200 meter Individual Medley and 4 x 100 meter Medley.[9]
International Swimming League
In 2019 he was a member of the inaugural International Swimming League representing the Cali Condors, who finished third place in the final match in Las Vegas, Nevada in December. Larkin was one of the top point scorers at each match for the Condors swimming backstroke, IM, and relays.[10]
Legend: OC – Oceanian record;NR – Australian record; Records not set in finals: h – heat;sf – semifinal;r – relay 1st leg;rh – relay heat 1st leg;b – B final;† – en route to final mark;tt – time trial