He is the silver medalist of the 2010 Winter Olympics in the team relay and the bronze medalist of the 2014 Winter Olympics in the 30 km skiathlon. The victory was regarded as a major surprise, despite Johnsrud Sundby delivering several solid displays in earlier races. He retained his Tour de Ski title in 2015 and 2016.
He is the first Norwegian to have won the Tour de Ski and the only man to have won it three times in a row. Along with Gunde Svan and Bjørn Dæhlie, he is the only man to have won the overall World Cup three times consecutively, having accomplished the feat from 2014 to 2016. Johnsrud Sundby got his international breakthrough when he won his first individual victory on 30 November 2008 in Kuusamo, Finland. At lower levels, Johnsrud Sundby has won a junior sprint event in 2003, a 30 km Scandinavian Cup race in 2007, and a 10 km FIS race in 2007. He later won the team sprint event at the test event in Liberec, Czechoslovakian Republic on 17 February 2008. Johnsrud Sundby and compatriot Therese Johaug became the first Norwegians to win the Tour de Ski when they won the men"s and women" competitions in the 2013-2014 edition of the race. Johnsrud Sundby subsequently won the overall and distance competitions in the 2013-2014 FIS Cross-Country World Cup. In addition to his Tour de Ski victories, Johnsrud Sundby won the inaugural Ski Tour Canada, despite starting behind Sergey Ustiugov and Petter Northug on the final stage.
