Archaelogical finds show that settlers inhabitated the area as far back as 7,000 years BC, indicating that they followed the receding glaciers North as the last Ice Age came to a close. Inscriptions on exposed granite walls from the era show scenes of fishing and reindeer hunting. (Many of these primitive drawings can be seen today near Straumshella at Kvaløya--see "Day Trips" section.)

The early seeds of township can be found in the establishment of Tromsø's first church in 1252. In addition to abundant fishing and subsistence farming, the town's geographical location made it a natural center of trade. Extensive commerce from hunting and whaling expeditions to the arctic, as well as the so-called Pomor-trade with the great neighbor to the east, attracted merchants from Germany, France, Britain and Russia. Tromsø finally gained full trading privileges and a town charter in 1794. The international influences created a lively local culture; a German visitor in the 19th century was so surprised to find such a well developed social and fashion scene that he proclaimed it "the Paris of the North," a nickname that stuck and that you will hear often to this day.

As the town grew, it acquired a Shipyard (1848), the Tromsø Museum (1872), and the World's Northernmost Beer Brewery (1877), Mack. In the 1890s, the town truly cemented its position as Porten til Ishavet -- the gateway to the Arctic. Many Arctic Expeditions started here, and famous explorers Fritjof Nansen, Roald Amundsen and Umberto Nobile all drew on the expertise found in the city.

The city limits originally covered only part of the island of Tromsø. After a number of consolidations of the nation's many municipalities in the 1960s, the city ultimately grew to cover and area over 2 500 square km, making it the largest city in the world.

Tromsø was occupied during the Nazi Germany occupation in World War II, but the city was spared the scorched earth tactics that the retreating Germans applied in the province of Finnmark to the north. In 1944, the British Airforce was finally able to catch up with and sink the gigantic German battleship "Tirpitz," which the Nazis had hidden in the fjords and sounds around Tromsø. 

The 1960s saw some notable improvements in communications for the city; Tromsøbrua, the bridge that connects the island to the mainland, was completed in 1961, and the Langnes airport opened in 1964, marking the end of the seaplane era for the city.

Further modernizations took place through the 1970s. A catastrophic fire in 1969 had consumed many wood buildings, and much of the city center had to be rebuilt. The establishment of the University of Tromsø in 1972, the world's northernmost university, helped propel city growth further.

Today, Tromsø is an important regional administrative seat, a center for education, and the home of one of the nation's largest hospitals. Alumni of the University have gone on to establish high-tech industries in such varied fields as biotechnology and aeronautics. However, traditional trades such as fishing, fish-processing, and more recently fish-farming, are still important to the local economy.

The population had grown to approximately 62,000 by the end of 2003.