In February 2016, Hartmann ran the fastest 200 metre time by an Australian since 2006, finishing a race in Adelaide in 20.45 seconds. In April 2016 he was selected as part of the Australian team for the 2016 Summer Olympics, to be held in Rio de Janeiro, Brazil. He was chosen to represent the nation in the men's 200 metre event after winning the Australian national title in a time of 20.46 seconds. He is the first male Australian competitor in the Olympic 200 metres since the 2004 Summer Olympics in Athens. Hartmann also won the Australian national title in the 100 metres but did not achieve the qualification time for the 2016 Olympics.