The purpose of this article is to give an overview of urbanisering in North Norway during the 20th century. First, the concepts of town and urbanization and their use in the regional context are discussed. The analysis is based on population statistics, but adopts a functional concept of the town. In 1900 there were a few, small towns in North Norway; only five had more than 2000 inhabitants. By comparing the different towns, the development is described and explained respectively for the periods before and after the Second World War, while the five war years are treated separately. The number of towns grew towards 1940, but the level of urbanisation was still under twenty percent. In 2000, nearly half of the population of North Norway lived in towns. The reasons for the growth of the towns can vary from the one to the other. Nonetheless, the towns are categorised in groups in which both peculiarities and similarities and continuity and interruption in the development are summarized.