The Kingdom of the Isles comprises the Hebrides, the islands of the Firth of Clyde and the Isle of Man from the 9th to the 13th centuries.

The islands are known to the Norse as the Suðreyjar, or "Southern Isles" as distinct from the Norðreyjar or Northern Isles of Orkney and Shetland.

The historical record is incomplete, and the kingdom is not a continuous entity throughout the entire period.

The islands concerned are sometimes referred to as the Kingdom of Mann and the Isles, although only some of the later rulers claime that title.

At times the rulers are independent of external control, although for much of the period they have overlords in Norway, Ireland, England, Scotland or Orkney.

At times there also appear to have been competing claims for all or parts of the territory.

The islands involved have a total land area of over 8,300 square kilometers (3,205 sq mi) and extend for more than 500 kilometers (310 mi) from north to south.Viking influence in the area commences in the late 8th century, and while there is no doubt that the Uí Ímair dynasty plays a prominent role in this early period, the records for the dates and details of the rulers are speculative until the mid-10th century.

Hostility between the Kings of the Isles and the rulers of Ireland, and intervention by the crown of Norway (either directly or through their vassal the Earl of Orkney) are recurring themes.Invasion by Magnus Barelegs in the late 11th century results in a brief period of direct Norwegian rule over the kingdom, but soon the descendants of Godred Crovan reassert a further period of largely independent overlordship.

This comes to an end with the emergence of Somerled, on whose death in 1164 the kingdom is split in two.

Just over a century later, the islands become part of the Kingdom of Scotland, following the 1266 Treaty of Perth.