joined Sam Herford at the Spit Baths alongside Murray Rose. At the 1956 Australian Championships, Devitt finished third in the 110-yard behind Henricks and Chapman, and fifth in the 220-yard behind Chapman to gain Olympic selection. After a ten-week national training camp at the Tobruk Pool in Townsville, Queensland, Devitt was named as the national captain for the 1956 Summer Olympics in Melbourne. Devitt's first event was the 100-metre freestyle, where he won his heat and then his semi-final to qualify in second place for the final, where he matched Henricks for the first 80 metres, before Henricks surged to claim gold. Chapman completed an Australian sweep by finishing third. For the 4×200-metre freestyle relay, Devitt had clocked the fourth fastest time at the Australian Championships. After swimming the fastest leg in the heats of the relay, he was selected along with Rose, Henricks and Kevin O'Halloran for the final. The Australians won the gold medal in a world record time, with Devitt clocking the fastest leg in the whole race. In January 1957, Devitt set a world record in both the 100-metre and 110-yard freestyle, and lowered the 100-metre freestyle world record to 54.6 seconds later that month at the Queensland Championships. He then won his first individual Australian title in the 110-yard freestyle. With Henricks and Rose swimming and studying in the United States, Devitt became the dominant Australian freestyler, and decided to continue his career until the 1960 Summer Olympics, supporting himself as a health inspector for the Townsville City Council. In 1958, after claiming the Australian 110-yard title, he claimed three golds at the 1958 British Empire and Commonwealth Games in Cardiff, Wales in the 110-yard freestyle, and the 4×110-yard freestyle and medley relays. In 1959, Devitt again lowered the 110-yard freestyle, but was later defeated at the Australian Championships by John Konrads, who won every freestyle title from the 110-yard to 1650-yard events. In 1960 Devitt reclaimed his 110-yard Australian title, and at the pre-1960 Summer Olympics camp in Townsville, broke the 4×100-yard freestyle relay along with Henricks, Geoff Shipton and David Dickson. At the 110-yard freestyle trial, he came third behind Henricks and Shipton, and was controversially selected as the second Australian representative, by selectors who ignored Shipton. He also finished fifth in the 220-yard freestyle and was initially left out of the 4×200-metre freestyle relay team. Devitt was again named the national captain.