[3] In May 2020, she announced that she would return to competition with long-distance cross-country ski squad Team Ragde Eiendom, with a focus on competing in Vasaloppet in March 2021.

Bjørgen led the overall World Cup by 66 points, ahead of Canada's Beckie Scott going into the final race of the season, the 2 x 7.5 km double pursuit.

In 2015 Bjørgen won her first Tour de Ski after nine attempts, defeating reigning champion and compatriot Therese Johaug by over one and a half minutes.

Her first gold medal in the World Championships came in the individual sprint in Val di Fiemme in 2003, where she also picked up a silver in the 4 × 5 km.

At the 2007 championships in Sapporo, Bjørgen won two bronze medals in team sprint (with Astrid Jacobsen) and in the 4 × 5 km.

In the World Championships 2011, held at Holmenkollen, Oslo, during February and March 2011, Bjørgen won gold medals in the Sprint, the 10-kilometre classic, the 15-kilometre pursuit and the 4 × 5-kilometre relay.

In the next event, the team sprint, Bjørgen and Hilde G. Pedersen came fourth, and despite winning a silver in the 10 km, the remainder of the games went poorly for her.

[7] However Bjørgen recovered to win the 45 km Vasaloppet from Oxberg to Mora on 4 March, eight days after the end of the Winter Olympics.

In the sprint she was up against a very strong field, consisting of Petra Majdič of Slovenia who had taken a serious fall earlier in the day during qualification, and Justyna Kowalczyk of Poland who was leading the overall World Cup standings coming into the race.

She closed out her trip in Vancouver by taking silver 0.3 seconds behind Poland's Justyna Kowalczyk in the women's 30 km event.

Bjørgen won gold at the 2014 Winter Olympics in Sochi in the 15 km skiathlon, the Team sprint and the 30km freestyle race.

[8] Bjørgen is a five-time Olympian, having competed in every Winter Olympics since Salt Lake City in 2002 where she won her first silver medal.

[11] In the 2009–2010 season Bjørgen had a Therapeutic Use Exemption (TUE) issued by the International Ski Federation (FIS) for the asthma medication Symbicort which contained substances on the World Anti-Doping Agency (WADA) prohibited list.

[16] Bjørgen lives with her partner Fred Børre Lundberg, a former Olympic champion in Nordic combined, in Holmenkollen, Oslo.