Here You can find a list of airlines which operated in Trondheim airport.
Copenhagen Kastrup - Scandinavian Airlines System, Norwegian AirShuttle
Helsinki Vantaa - Finnair
London Gatwick - Norwegian AirShuttle
Manchester - Norwegian AirShuttle
Amsterdam Schiphol - KLM Royal
Riga - AirBaltic, Norwegian AirShuttle
Ålesund - Scandinavian Airlines System, Widerøe
Alta - Widerøe
Bardufoss - United Airlines
Bergen - Scandinavian Airlines System, Widerøe, Norwegian AirShuttle
Bodø - Widerøe, Scandinavian Airlines System, Norwegian AirShuttle
Brønnøysund - Widerøe
Florø - Widerøe
Hammerfest - Widerøe
Harstad/Narvik Evenes - Widerøe
Hasvik - Widerøe
Haugesund - Widerøe
Kristiansand Kjevik - Widerøe
Mo i Rana - Widerøe
Mosjøen Kjærstad - Widerøe
Namsos - Widerøe
Oslo Gardermoen - Norwegian AirShuttle, Scandinavian Airlines System, Widerøe
Rørvik Ryum - Widerøe
Sandefjord Torp - Widerøe
Sandnessjøen Stokka - Widerøe
Stavanger Sola - Scandinavian Airlines System, Norwegian AirShuttle, Widerøe
Svalbard Longyearbyen Spitsbergen - Norwegian AirShuttle
Tromsø-Langnes - Widerøe, Scandinavian Airlines System, Norwegian AirShuttle
Vadsø - Widerøe
Gdansk - WizzAir
Krakow - Norwegian AirShuttle
Warsaw Chopin - EnterAir
Stockholm Arlanda - Scandinavian Airlines System
Alicante - Norwegian AirShuttle
Las Palmas Gran Canaria - Norwegian AirShuttle, Scandinavian Airlines System, Eastland Air
Malaga Costa del Sol - Norwegian AirShuttle
Tenerife South - Eastland Air
Frankfurt am Main - EnterAir
Munich - EnterAir