List of islands of Wales

This is a list of islands of Wales, the mainland of which is part of Great Britain, as well as a table of the largest Welsh islands by area. The list includes tidal islands such as Sully Island but not locations such as Shell Island which, though they are termed islands, are peninsulas.

Name	Island group/location
Anglesey	Irish Sea
Ballast Bank/Lewis's Island	Porthmadog
Bardsey Island	Gwynedd
Barry Island	Vale of Glamorgan
Burry Holms	Gower
Caldey Island	Pembrokeshire
Cardigan Island	Ceredigion
Carreg Onnen	Pembrokeshire
Carreg Rhoson	Pembrokeshire
Carreg yr Halen	Anglesey
Church Island	Anglesey
Cribinau	Anglesey
Daufraich	Pembrokeshire
Denny Island	Monmouthshire
East Mouse	Anglesey
Emsger	Pembrokeshire
Flat Holm	Bristol Channel
Gateholm	Pembrokeshire
Grassholm	Pembrokeshire
Holy Island	Anglesey
Maen Gwenonwy	Llŷn Peninsula
Middle Head	Gower
Middle Mouse	Anglesey
Middleholm	Pembrokeshire
Mumbles Head Island	Gower
North Stack	Anglesey
Puffin Island	Anglesey
Ramsey Island	Pembrokeshire
St Catherine's Island	Pembrokeshire
St Margaret's Island	Pembrokeshire
St Tudwal's Island East	St Tudwal's Islands
St Tudwal's Island West	St Tudwal's Islands
Salt Island	Anglesey
Sheep Island	Pembrokeshire
The Skerries	Anglesey
Skokholm	Pembrokeshire
Skomer	Pembrokeshire
South Stack	Anglesey
Sully Island	Vale of Glamorgan
Thorn Island	Pembrokeshire
Tusker Rock	Vale of Glamorgan
West Mouse	Anglesey
Worms Head	Gower
Ynys Benlas	Anglesey
Ynys Beri	Pembrokeshire
Ynys Cantwr	Pembrokeshire
Ynys Castell	Anglesey
Ynys Dulas	Anglesey
Ynys Eilun & Pont yr Eilun	Pembrokeshire
Ynys Faelog	Anglesey
Ynys Feurig	Anglesey
Ynys Gaint	Anglesey
Ynys Gifftan	Gwynedd
Ynys Gored Goch	Anglesey
Ynys Gwelltog	Pembrokeshire
Ynys Llanddwyn	Anglesey
Ynys Lochtyn	Ceredigion
Ynys Meicel	Pembrokeshire
Ynys Moelfre	Anglesey
Ynys Onnen	Pembrokeshire
Ynys Welltog	Anglesey
Ynys y Bîg	Anglesey

Largest islands in Wales

Holy Island and Anglesey are often counted together as they are separated by such a narrow channel.

Inland islands

There are no islands of any great size in lakes in Wales. The crannog in Llangorse Lake is an artificial island. Several reservoirs contain islets e.g. Llyn Brenig, Elan Valley Reservoirs and Llyn Trawsfynydd, the last named having the largest and most numerous, though some are linked by causeways.