The cheapest flight to Oslo you can get by boooking 41 days before departure.
The most popular airlines on the route Sofia - Oslo: Bulgaria Air (FB), Lufthansa (LH), KLM (KL).
The cheapest flights you can book on the route Sofia Airport (SOF) - Gardermoen (OSL).
There is no direct flight on the route from Sofia to Oslo
Il volo con scalo più breve dura 5h 50min.