The OSL Lounge at Oslo International Airport serves a plethora of airlines including British Airways, Air Berlin, Finnair, Qatar Airlines and nearly every other airline at Oslo which is not part of the Star Alliance, as Star Alliance airlines tend to utilize the SAS lounge at OSL. Despite the number of airlines that use the lounge, the lounge was nearly empty when I visited it around 9 am in the middle of the week. The lounge is located on the 2nd floor of the Schengen area after security but before passport control. Do note that non-Schengen passengers must clear customs closer to their gates, and depending on how fast you walk, it is about a 10 minute walk + possible custom wait times if you are departing to areas outside of the Schengen region!
The lounge offers several seating areas made for groups, couples or those traveling alone. There is also some red recliners that are made for napping for the those who need additional time to sleep.
There is a small self serve food buffet with cold items to snack on. Nothing of substance but at least a decent snack/breakfast.
For those feeling parch, dive into the self serve beer or wine on tap or opt for water, coffee, or other local beverages.
The lounge offers flight monitors for all flights, bathrooms but not showers, and no TV/Entertainment/work stations from what I saw. Do not stay too long in this lounge though, as the Oslo Airport is actually quite modern and has some other areas worth exploring! But if you looking to get away from the busy terminal below, you’ll find some R&R time with descent snacks and beverages at the OSL Lounge.