The Town of Kajaani was founded by Count Per Brahe in 1651. The River Kajaaninjoki and the ruins of the historical Kajaani Castle are situated in heart of the town. Kajaani Castle will celebrate its 400th anniversary in 2004.

Many notable personalities have contributed to the development of Kajaani. Elias Lönnrot, the compiler of Kalevala, acted as a district physician in Kajaani in 1833-53, from where he set out for his poem-collecting journeys to Viena Karelia. Poet Eino Leino was born in Hövelö, Paltaniemi, and late president Urho Kaleva Kekkonen attended the 2nd grade of the local secondary school and also matriculated from Kajaani in 1919.

Kajaani houses a range of industrial and service enterprises and educational institutions. One of the most important lines of business is the woodprocessing industry. In addition, the town has several internationally renowned companies that have top-flight expertise in measurement technology, for instance. Kajaani is the centre of a region with 87,371 inhabitants distributed between 10 municipalities.