Cologna won his fourth Tour de Ski title by winning the 2017–18 edition. He won two of the six stages of the Tour, both in Lenzerheide, and won the overall standings with a margin of one minute and 26.5 seconds to second-placed Martin Johnsrud Sundby. Alongside female skier Justyna Kowalczyk, Cologna is the only athlete to win the Tour de Ski four times. At the PyeongChang Olympics Cologna won the 15 kilometre freestyle. He became the first cross-country skier to win three consecutive 15 km Olympic events. On 10 March 2018, he became the first Swiss to win the prestigious Holmenkollen 50 km.