Oslo Airport (Gardermoen, OSL) sits about 45 km north of the city and has roughly 20,000 spaces across two car-park buildings and eight outdoor areas, operated by OnePark. Short-term and KISS&FLY are right by the terminal; the cheaper long-term areas use a shuttle bus.
Open the map for Oslo Airport to compare parking near Parking at Oslo Airport (Gardermoen). Book ahead and pick your P-area before you travel; for multi-day trips a long-term area with the shuttle bus usually beats parking right at the terminal.
For a quick hand-off, KISS&FLY by the terminal is free for up to 7 minutes. For multi-day trips, a long-term area with the shuttle bus (such as P4) is usually cheaper than parking right at the terminal. Booking ahead means a space is reserved before you travel. Open the map for Oslo Airport to compare garages and surface lots near Parking at Oslo Airport (Gardermoen).