Arran or the Isle of Arran (Scots Gaelic: Eilean Arainn) is the largest island in the Firth of Clyde, Scotland, and with an area of 432 square kilometres (167 sq mi) is the seventh largest Scottish island. It is in the unitary council area of North Ayrshire and the 2001 census had a resident population of 5,058. Although commonly associated with the Hebrides, with which it shares many cultural and physical similarities, these latter islands are located to the north and west beyond Kintyre. Arran is mountainous and has been described as a "geologist's paradise".
There has been continuous habitation since the early Neolithic period, from which time on there are numerous prehistoric remains. From the 6th century on Goidelic-speaking peoples from Ireland colonised the island and it became a centre of religious activity. During the troubled Viking Age Arran became the property of the Norwegian crown before becoming formally absorbed by the kingdom of Scotland in the thirteenth century. The 19th century "clearances" led to significant reductions in population and the end of the Gaelic language and way of life.
The economy and population have recovered in recent years, the main industry being tourism. There is diversity of wildlife, including three species of tree endemic to the area.