It has taken nine editions of the annual event for the world's most successful cross-country skier to win her first Tour de Ski.
"It is a big victory for me. To win the Tour de Ski has been a goal for me for a long time," Bjoergen said. "It took me nine years to achieve it. I knew I had to be strong before the last stage. I started the Tour were well. I felt good on the climb.
"It is an amazing feeling and it is great to share the happiness with my teammates. They mean a lot for me. They motivate me and they push me in training every day."
Bjoergen started the day more than two minutes in front of Heidi Weng and finished with an advantage of 1 minute, 39.2 seconds over defending champion Therese Johaug, who was fastest on the final stage.
Weng, who was second on the day, finished third overall, 1:59.5 behind Bjoergen — who was third fastest on the traditional climb up Alpe Cermis.
Elizabeth Stephen of the United States was fourth, propelling her into fifth overall, the best ever finish for an American. She was the highest non-Norwegian finisher, with Ragnhild Haga claiming fourth.
The men's event was closer. Sundby began just 3.1 seconds behind his teammate Petter Northug but overtook him to join Dario Cologna as the only male skiers to win consecutive Tour titles.
"Today feels just amazing," Sundby said. "I did not have the best start today. I did not feel good at the beginning. Petter was pushing hard after the start and I did not know if I could follow him. I am so happy and relieved to win. Mentally it was the biggest challenge ever."
Sundby, who was third on the day behind Roland Clara and Maurice Manificat, finished 34.5 seconds ahead of Northug in the overall standings.
"I am very happy to be second in the Tour," Northug said. "Me and Martin were working very well together before the start of the climb. Martin sped up on the hill. I could not follow him but I found a good rhythm and I am happy to be second."
Russia's Evgeniy Belov was third, 51.1 behind Sundby.
Ivan Babikov of Canmore, Alta., was 12th on the day and 31st overall. Devon Kershaw, of Sudbury, Ont., was 40th on the day and 35th overall.