The outlying islands of Scotland are not part of the larger archipelagos and island groups of Scotland—the Hebrides, the Northern Isles or the Islands of the Forth and Clyde estuaries. None of these islands are currently inhabited and few of them ever were, although Hirta was occupied from the Neolithic age until 1930 and Stroma was permanently occupied until the 1970s and thereafter by lighthouse keepers and their families until 1996. Several other outlying islands have lighthouses, none of which is still staffed.
In this list, an island is defined as "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". A complication relating to membership of this list is that there are various descriptions of the scope of the Hebrides, the large group of islands that lie off Scotland's west coast. The Collins Encyclopedia of Scotland describes the Inner Hebrides as lying "east of The Minch", which would include any and all offshore islands. There are various islands that lie in the sea lochs such as Eilean Bàn and Eilean Donan that might not ordinarily be described as "Hebridean" but no formal definitions exist and for simplicity they are included in the List of Inner Hebrides rather than here.
There are several small groupings of outlying islands involved. The most significant of these is the St Kilda archipelago which lies 64 kilometres (40 mi) west-northwest of North Uist and is now a World Heritage Site. It is one of the few to hold joint status for its natural and cultural qualities. At 196 metres (643 ft) Stac an Armin is the highest sea stack in the British Isles and in July 1840, the last great auk seen in the British Isles was captured there.
East of St Kilda are the Flannan Isles, where all three lighthouse keepers mysteriously vanished without trace in December 1900. Further north and east are the two outliers of Sula Sgeir and North Rona, which have strong cultural links to the Outer Hebrides. North Rona is 71 kilometres (44 mi) north north east of Butt of Lewis and 18 kilometres (11 mi) east of Sula Sgeir. It is the remotest island in the British Isles ever to have been inhabited on a long-term basis. It is also closer than any other part of Scotland to the Faroe Islands. Sule Skerry and Sule Stack lie further east and are administratively part of Orkney.
The islands of the north coast are remote from the main centres of population, although they mostly lie close to the mainland. There is a small group of larger islands near Tongue Bay, but the largest on this coast is Stroma in the Pentland Firth, between Caithness and Orkney. Innis Mhòr in the Dornoch Firth is the largest of a handful of small islets off the coast of Easter Ross. Further south are Inchcape off the coast of Angus, and Mugdrum, the only substantial island in the Firth of Tay. There is a cluster of islands in the Solway Firth that marks the south western border of Scotland, including the Islands of Fleet, in Wigtown Bay.
Most of the smaller islets that surround those in the main list are obscure and none have been permanently inhabited in modern times. Nonetheless, some have a degree of historical significance. Castle Mestag off Stroma is the ruins of a once fortified stack accessible only via a drawbridge. Some islets are identified as "storm washed", meaning that although they are partly above mean sea level, large waves wash over the top of them during storms, rendering them uninhabitable.
Finally, there is remote Rockall, which is 367 kilometres (228 mi) to the west of North Uist. It is a small rocky islet in the North Atlantic which could be, in James Fisher's words, "the most isolated small rock in the oceans of the world" and which was declared part of Scotland by the Island of Rockall Act 1972. However, the legality of the claim is disputed by the Republic of Ireland, Denmark and Iceland and it is probably unenforceable in international law.
North coast (from west to east): Stac an Dunain, Duslic, Stack Clò Kearvaig, An Garbh-eilean, Na Glas Leacan, Eilean Dubh, Clach Bheag na Faraid, Clach Mhòr na Faraid, Àigeach, Eilean Polsain, Boursa Island, Glas-eilean Mòr, Garbh-eilean, Wester Clett, Middle Clett, Easter Clett, Little Clett, Clett.
East coast:
North Moray Firth (from north to south): The Knee, Stacks of Duncansby, Stack o' Brough, South Stack, The Stacks, Eilean na h-Aibhne, Three Kings.
South Moray Firth (from west to east): Covesea Skerries, Halliman Skerries, Boar's Head Rock, West Muck, East Muck, Craigenroan, Bow Fiddle Rock, Collie Rocks, Craigandargity.
Kinnaird Head to the Bullers of Buchan: The Ron, The Skerry, Miekle Mackie, Miekle Donnon, Little Donnon, Craig Snow, Meikle Dumeath, Little Dumeath.
Bullers of Buchan to Girdle Ness: Dunbuy, The Donnons, Skellyis of Harrol.
Other than Mugdrum in the Firth of Tay and the Islands of the Forth there are no genuine islands on the east coast of Scotland south of Buddon Ness.
Tidally exposed islets and skerries
There are various smaller islets and skerries in the seas surrounding the mainland of Scotland that are only exposed at lower stages of the tide. Craiglethy is part of the Fowlsheughnature reserve. The Three Kings, off the coast of Easter Ross near Balintore, is also known as Creag Harail or Harold's Rock and called The King's Sons in the New Statistical Account of Scotland. According to legend, three sons of a Danish prince, sailing to avenge their sister's wrongs, were wrecked here and gave these rocks their collective name. Their graves were marked by the sculptured stones of Nigg, Shandwick and Hilton of Cadboll. Another story has their burial at Nigg Rocks below the North Sutor.
Quine, David (2000) St Kilda. Grantown-on-Spey. Colin Baxter Island Guides. ISBN1-84107-008-4
Rackwitz, Martin (2007) Travels to Terra Incognita: The Scottish Highlands and Hebrides in Early Modern Travellers' Accounts C. 1600 to 1800. Waxmann Verlag. ISBN978-3-8309-1699-4
^Various other definitions are used in the Scottish context. For example, the General Register Office for Scotland define an island as "a mass of land surrounded by water, separate from the Scottish mainland" but although they include islands linked by bridges etc., this is not clear from this definition. Haswell-Smith (2004) uses "an Island is a piece of land or group of pieces of land which is entirely surrounded by water at Lowest Astronomical Tide and to which there is no permanent means of dry access". This consciously excludes bridged islands, which most other sources include.
^In addition to World Heritage Status, which none of the other outlying islands share, Hirta is by far the largest individual island (Soay and Boreray are fourth and fifth largest), and at its maximum of 180 its population was by far the largest, only Stroma coming close. Numerous books have been written about these islands, their history and wildlife, which at one time included three unique sub-species – two mice and the St Kilda wren.
^When inhabited, these islands had strong cultural ties to the Hebrides, but they are quite distinct from the Outer Hebrides geologically and Haswell-Smith (2004) lists St Kilda in "Section 9: The Atlantic Outliers".
^Possibly also known as "The Robber's Castle" and said to have been a hideout of the 12th-century pirate Sweyn Asleifsson.
^There are numerous islands that are more remote from a mainland, but not from other islands. Rockall lies "the furthest distance from any other outcrop or land of any description".
^Aird an Runair, North Uist NF686705 is the nearest place on an inhabited British island to Rockall, about 367 km (228 mi) (198 nmi) away. Gob a' Ghaill, on uninhabited Soay, St Kilda and the nearest point of undisputed British soil at NA055014 is about 301 km (187 mi) (162 nmi) away.
^Note that the Ordnance Survey maps mark the height above sea level of a high point on most islands, but in a small number of cases, this may not be the highest point.
^Indicates the presence of a lighthouse on Ordnance Survey maps.
^Indicates the last known date of permanent, year round settlement.
^The Ordnance Survey indicate the remains of an 8th-century chapel, which is also the site of an 18th-century "tavern" and there is an uninhabited cottage facing the sea.
^Fleming identifies a wheelhouse on the island. Various tales told by the St Kildans hint at occupation in the historic period, although no concrete evidence of this has been found. There is nowhere to store a boat and any permanent residents would have been marooned there and dependent on outside assistance to leave. As a result of a smallpox outbreak on Hirta in 1724, three men and eight boys were marooned on Boreray until the following May.
^The island's name means "fort" but there is only a single ruined wall of a structure said to have been built in the far-distant past by the mythical Fir Bolg.
^The Ordnance Survey indicate the presence of a ruined chapel.
^The two islands are connected to one another and the mainland at low tides and were probably inhabited at some point in the past. The Gaelic name is Eilean nan Gall meaning "islands of the strangers", which is thought to refer to their usage by Danish Vikings.
^None of the very small islets are named by the Ordnance Survey.
^An area estimate of 624 square metres (6,720 sq ft). The height is circa 20 metres (66 ft).
^Like nearby Boreray there is nowhere to store a boat and any permanent residents would have been marooned there and dependent on outside assistance to leave. There is a primitive hut known as Taigh Dugan (Dugan's house). This is little more than an excavated hole under a huge stone with two rude walls on the sides. The story of its creation relates to two sheep-stealing brothers from Lewis who came to St Kilda only to cause further trouble. Dugan was exiled to Soay, where he died; the other, called Fearchar Mòr, was sent to Stac an Armin, where he found life so intolerable he cast himself into the sea.
^It would be impossible to maintain life for long on this precipitous crag although there are 78 storage cleitean and a small bothy used by the native St Kildan fowlers in the summer.
^A figure of 124.4 hectares (307 acres) for Rona and Sula Sgeir is provided by Wood. Haswell Smith gives 109 hectares (270 acres) for North Rona. Sula Sgeir is therefore c. 15.4 hectares (38 acres).
^"St Kilda"Archived 2007-07-05 at archive.today (pdf) United Nations Environment Programme World Conservation Monitoring Centre. Retrieved 4 August 2009.
^"Rabbit Islands" www.electricscotland.com, quoting the Ordnance Gazetteer of Scotland, which itself refers to a survey of 1880. Retrieved 30 July 2010.
