Many scientists believe that the very first Norwegian lived near the city of Kristiansund. At the end of the last Ice age some areas at the western coast of Norway were ice-free. There was also a lot of food in the sea around Kristiansund at that time, and it is believed that the first settlement arrived in Kristiansund around year 8000 BC.

During the Viking ages there were many important battles around Kristiansund. The most famous one was the Battle of Rastarkalv on the island of Frei, where the Norwegian King Håkon the Good fought against the Eirikssønnene-group. There is now a memorial monument located near Rastakalv, where the battle was fought.

The island of Grip was an important fishing community during the Middle Ages, and were considered to be the most important municipality in the region at the time. The natural harbour in Lille-fosen, close to where Kristiansund is located today were also frequently used for fishing purposes.

During the 17th century a small settlement developed around the area we know today as Kristiansund harbour. As more and more settlers arrived, the area became an important trading port for fishing and the lumber transportation along the coast. The Dano-Norwegian government established a customs station here, which was controlled by the main trading port in Trondheim.

Dutch sailors brought the knowledge of clipfish production to Kristiansund at the end of the 17th century, and for a number of years the city was the largest exporter of clipfish in Norway, exporting goods mainly to the Mediterranean countries. The citys clipfish production was also part of the reason why it was awarded town status in 1742.

There are two local TV stations in Kristiansund. The largest one is TVNordvest, (TV North-West) which broadcasts local news from the area around Kristiansund on a daily basis, as well as some other TV shows. The second one is TV Kristiansund, which is more of a culture channel, broadcasting cultural news from Kristiansund, like shows from the city Opera.

The local newspaper of Kristiansund is Tidens Krav, which also functions as a local newspaper for the other municipalities located nearby the city.