John Thomas Devitt, AM (born 4 February 1937) is an Australian sprint freestyle swimmer of the 1950s and 1960s, who won a gold medal in the 100-metre freestyle at the 1960 Summer Olympics in Rome.
He won in controversial circumstances, being awarded the gold medal despite the timekeepers recording a slower time than the American silver medallist Lance Larson.
He also claimed a gold medal at the 1956 Summer Olympics in Melbourne, in the 4×200-metre freestyle relay.