Tromsø is a city in Tromsø Municipality in Troms og Finnmark county, Norway. The city is the administrative centre of the municipality as well as the administrative centre of Troms county. The Diocese of Nord-Hålogaland and its Bishop are based at the Tromsø Cathedral in the city. The city is located on the island of Tromsøya which sits in the Tromsøysundet strait, just off the mainland of Northern Norway. The mainland suburb of Tromsdalen is connected to the city centre on Tromsøya by the Tromsø Bridge and the Tromsøysund Tunnel. The suburb of Kvaløysletta on the island of Kvaløya is connected to the city centre by the Sandnessund Bridge.
The 21.25-square-kilometre town has a population of 64,448 which gives the town a population density of 3,033 inhabitants per square kilometre. The city centre has a population of 38,980. The mainland borough of the city, Tromsdalen, has a population of 16,787 and the suburb of Kvaløysletta on the island of Kvaløya has a population of 8,681. The most populous town north of Tromsø in Norway is Alta, with a population of 15,094, making Tromsø a very large city for this vast rural northern part of Norway.