Mo i Rana is a town and administrative centre of the municipality of Rana in Nordland county, Norway. It is located just south of the Arctic Circle and in the Helgeland region of Nordland. Some of the outlying areas of the town include the suburbs of Båsmoen and Ytteren in the north and Selfors in the east.
The town is called "Mo i Rana" to distinguish it from other places named Mo—most notably the town of Mosjøen, also in Helgeland—though locally the town is usually just calledMo. The postal address for Mo was "Mo 8600" until it was changed to "Mo i Rana 8600" in 1999.
The 13.32-square-kilometre (3,290-acre) town has a population (2011) of 18,141. The population density is 1,362 inhabitants per square kilometre (3,530 /sq mi). This makes it the largest town in Helgeland and the second largest (after Bodø) in Nordland.
The name "Mo" comes from an old farm that was situated near the modern town. The name of the farm comes from the Old Norse name Móar, which means sand or grass lowland. The name Rana probably comes from Old Norse too. Rana means quick or fast, probably because the fast water flow in the Ranfjorden outside town. The town was an old trade centre in Helgeland. Farmers have lived in the area since the Iron Age