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 (Ynys Môn) Irish Sea Ballast Bank/Lewis's Island (Cei Ballast) Porthmadog (artificial island formed from ships ballast) Bardsey Island (Ynys Enlli) Gwynedd Barry Island (Ynys y Barri) Vale of Glamorgan (linked to the mainland since the 1880s) Burry Holms Gower Caldey Island (Ynys Bŷr) Pembrokeshire Cardigan Island (Ynys Aberteifi) Ceredigion Carreg Onnen Pembrokeshire Carreg Rhoson Pembrokeshire Carreg yr Halen Anglesey Church Island (Ynys Dysilio) Anglesey Cribinau (Ynys Cribinau) Anglesey Daufraich Pembrokeshire Denny Island (Ynys Denny) Monmouthshire East Mouse (Ynys Amlwch) Anglesey Emsger Pembrokeshire Flat Holm (Ynys Echni) Bristol Channel Gateholm Pembrokeshire (tidal island) Grassholm (Gwales/Ynys Gwales) Pembrokeshire Holy Island (Ynys Gybi) Anglesey Maen Gwenonwy Llŷn Peninsula (tidal island) Middle Head Gower (tidal island) Middle Mouse (Ynys Badrig) Anglesey Middleholm (aka Midland Isle) Pembrokeshire Mumbles Head Island (Y Mwmbwls) Gower (tidal island) North Stack (Ynys Arw) Anglesey Puffin Island (Ynys Seiriol) Anglesey Ramsey Island (Ynys Dewi) Pembrokeshire St Catherine's Island (Ynys Catrin) Pembrokeshire St Margaret's Island (Ynys Farged) Pembrokeshire St Tudwal's Island East (Ynys Tudwal Fach) St Tudwal's Islands St Tudwal's Island West (Ynys Tudwal Fawr) St Tudwal's Islands Salt Island (Ynys yr Halen) Anglesey Sheep Island (Ynys y defaid) Pembrokeshire (tidal island) The Skerries (Ynysoedd y Moelrhoniaid) Anglesey Skokholm (Ynys Sgoc-holm) Pembrokeshire Skomer (Ynys Skomer) Pembrokeshire South Stack (Ynys Lawd) Anglesey Sully Island Vale of Glamorgan (tidal island) Thorn Island Pembrokeshire Tusker Rock (Ynys Twsgr) Vale of Glamorgan West Mouse (Maen y Bugail) Anglesey Worms Head (Pen Pyrod) Gower (tidal island) 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 (tidal island) Ynys Gored Goch Anglesey Ynys Gwelltog Pembrokeshire Ynys Llanddwyn Anglesey (tidal island) Ynys Lochtyn Ceredigion Ynys Meicel Pembrokeshire Ynys Moelfre Anglesey Ynys Onnen Pembrokeshire Ynys Welltog Anglesey Ynys y Bîg Anglesey

Largest islands in Wales Island Area (sq mi) Area (km2) 1 Anglesey 260.37 674.36 2 Holy Island 15.22 39.44 3 Skomer 1.12 2.90 4 Ramsey Island 0.99 2.58 5 Caldey Island 0.84 2.18 6 Bardsey Island 0.79 2.06 7 Skokholm 0.41 1.06 8 Flat Holm 0.21 0.339Ynys Llanddwyn0.190.310 Puffin Island 0.11 0.28 11 Cardigan Island 0.06 0.15

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.

See also

List of the British Isles

References