The Flybus airport shuttle takes you from BSÍ Bus Terminal to Keflavík International Airport (KEF). Seats are guaranteed and buses operate for every flight departure and arrival. The transfer from downtown Reykjavik to the airport takes approximately 45 minutes from the BSÍ Bus Terminal.
Departures from BSÍ Bus Terminal to Keflavik Airport are in connection with all departing passengers flights. You can find the bus stop right outside the terminal building.