Martin Johnsrud Sundby is a Norwegian cross-country skier who has competed since 2003. 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. He got his international breakthrough when he won his first individual victory in November 2008 in Kuusamo, Finland. Martin Johnsrud Sundby together with Therese Johaug became the first Norwegians to win the Tour de Ski when they won the men's and women' competitions in the 2013-14 edition of the race. Sundby subsequently won the overall and distance competitions in the 2013–14 FIS Cross-Country World Cup, and he retained his Tour de Ski title in 2015. He represents the sports club Røa IL and is part of the Norwegian National Cross-Country Ski Team that competes at the highest international level.