List of Orkney islands

Orkney, an archipelago located 16 kilometres (9.9 mi) north of mainland Scotland, comprises more than 70 islands and skerries, of which 20 are permanently inhabited. In addition to the Mainland, the largest island in Orkney, there are three groups of islands. The North and South Isles lie respectively north and south of the Mainland, and the Pentland Skerries are a group of small islands in the Pentland Firth, a dangerous stretch of water between mainland Scotland and the larger islands of Orkney, through which run the strongest tidal streams in Britain. The island of Stroma may be mistakenly included in Orkney, but is in fact part of Caithness.

The definition of an island used in this list is that it is "land that is surrounded by seawater on a daily basis, but not necessarily at all stages of the tide, excluding human devices such as bridges and causeways". Four islands are joined to the Mainland by a series of causeways known as the Churchill Barriers. They are South Ronaldsay, Burray, Lamb Holm and Glimps Holm. In addition, Hunda is connected to Burray by a causeway. The barriers were constructed by Italian prisoners of war as a means of preventing enemy submarine access to the vast natural harbour of Scapa Flow after the sinking of HMS Royal Oak by a German U-boat in 1939 with the loss of 883 lives. The Italian prisoners constructed a small Catholic chapel on Lamb Holm during their incarceration.