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.

Tromsø is even milder than places much farther south of it elsewhere in the world, such as on the Hudson Bay and in Far East Russia, with the warm-water current allowing for both relatively mild winters and tree growth in spite of its high latitude.

Torbjørn Brundtland and Svein Berge of the electronica duo Röyksopp and Lene Marlin grew up and started their careers in Tromsø.

Archeological excavations in Tønsvika, just outside the city limits, have turned up artifacts and remains of buildings estimated to be 9,000 to 10,000 years old.

The Norse chieftain Ohthere, who lived during the 890s, is assumed to have inhabited the southernmost reaches of today's Tromsø municipality.

[7] An Icelandic source (Rimbegla) from the 12th century also describes the fjord Malangen in the south of today's Tromsø municipality as a border between Norse and Sámi coastal settlements during that part of the Middle Ages.

Tromsø was not just a Norwegian outpost in an area mainly populated by the Sámi, but also a frontier city towards Russia; the Novgorod state had the right to tax the Sámi along the coast to Lyngstuva and inland to the Skibotn River or possibly the Målselv River, whereas Norway was allowed to tax areas east to – and including – the Kola Peninsula.

[8] During the next five hundred years Norway's border with Russia and the limits of Norwegian settlement would be pushed eastwards to Sør-Varanger Municipality, making Tromsø lose its character as a "frontier town".

[citation needed] During the 17th century, while Denmark–Norway was solidifying its claim to the northern coast of Scandinavia and during this period a redoubt, Skansen, was built.

Despite only being home to around 80 people, Tromsø was declared a kjøpstad and issued its city charter in 1794 by King Christian VII.

This coincided with, and was a direct consequence of, the abolition of the city of Bergen's centuries-old monopoly on the trade in cod.

[11] The city was established as Tromsø Municipality 1 January 1838 (see formannskapsdistrikt), but at that time it was a very small size in area.

How this nickname came into being is uncertain, but the reason is generally assumed to be that people in Tromsø appeared far more sophisticated than visitors from the south typically expected.

Explorers like Roald Amundsen, Umberto Nobile and Fridtjof Nansen made use of the know-how in Tromsø on the conditions in the Arctic, and often recruited their crews in the city.

General Carl Gustav Fleischer arrived in Tromsø on 10 April 1940 after flying in terrible conditions.

From Tromsø he issued orders for total civilian and military mobilisation and declared Northern Norway a theatre of war.

The Germans eventually captured all of Norway, after allied support had been withdrawn, although they encountered fierce resistance from the Finnmark-based Alta Battalion at Narvik.

On 1 January 1955, the Bjerkaker area on the island of Tromsøya (population: 1,583) was transferred from Tromsøysund to the city of Tromsø.

Owing to Tromsø's high latitude, twilight is long, meaning there is no real darkness between late April and mid-August.

Additionally, due to the coastal location, Tromsø is often subject to cloudy conditions which prevents aurora being seen, even if they are present.

The cinema has large wall paintings, made by the local artist Sverre Mack in 1921, which picture scenes from Norwegian folk lore and fairy tales.

The Arctic Cathedral, a modern church built in 1965, is situated on the mainland, facing the sound and city centre.

A cable car goes up to mount Storsteinen, 420 metres (1,380 feet) above sea level, with a panoramic view over Tromsø.

The mountain Tromsdalstinden, 1,238 metres (4,062 ft), on the mainland, which is easily spotted from the city centre, is also a major landmark.

An alternative option is to use the local bus routes 40 and 42, which stop just a few minutes walk from the terminal, and are considerably cheaper.

Its most common destination is smaller towns in Troms, Finnmark and Nordland, served by Widerøe; as of December 2023, competing airlines and foreign airlines offer longer direct flights to southern Norway, Longyearbyen, Finland (Helsinki and Rovaniemi), Copenhagen, Luton Airport, and north and central Europe (including Frankfurt, Paris, Amsterdam and Zürich).

Tromsø Midnight Sun Marathon is arranged every year in June and recently also a Polar Night Halfmarathon in January.