How to get from Gardermoen Airport to Oslo
There are trains and buses from Gardermoen Airport to Oslo. The cheapest mode of transport is regular (not express) NSB trains. It’s about getting them to Jernbanetorget (Oslo central train station) that I’ll tell you about.
After picking up your luggage at the conveyor belt, follow the Exit signs along the conveyor belt. There will be customs, cheerfully walk through the green corridor. Go out into the airport hall - this is a common area, you can consider yourself “outside”. Turn right and follow the signs for Trains and Flytoget. In less than 100 meters you will see a fork ahead and signs for Flytoget (pronounced "flitUget").