At the 2017 World Championships in Lahti Niskanen won a bronze medal in the team sprint together with team mate Jauhojärvi. Niskanen led the race into its final stages, but a crash with Norway's Emil Iversen saw Russia and Italy surpass them. On 1 March, he became World champion on the 15 km classic event, winning the gold medal 17.9 seconds ahead of Martin Johnsrud Sundby. He won his second "Finnish Sports Personality of the Year" in 2017.