Voici une liste des îles appartenant au pays de Galles, avec leur superficie en kilomètres carrés, leur localisation et leur nom gallois lorsqu'il diffère du nom le plus couramment utilisé.
| Nom
|
Localisation
|
Superficie
|
| Anglesey (Ynys Môn) |
Anglesey |
713,80
|
| Bardsey (Ynys Enlli) |
Gwynedd |
1,99
|
| Bishops and Clerks |
Pembrokeshire |
|
| Caldey (Ynys Bŷr) |
Pembrokeshire |
2,18
|
| Cardigan Island (Ynys Aberteifi) |
Ceredigion |
0,15
|
| Carreg Ddu |
Gwynedd |
|
| Church Island (Ynys Dysilio) |
Anglesey |
0,01
|
| Craig yr Iwrch |
Anglesey |
|
| Cribinau |
Anglesey |
|
| East Mouse (Ynys Amlwch) |
Anglesey |
|
| Emsger |
Pembrokeshire |
|
| Flat Holm (Ynys Echni) |
Cardiff |
0,33
|
| Gateholm |
Pembrokeshire |
|
| Grassholm (Ynys Gwales) |
Pembrokeshire |
0,09
|
| Holy |
Anglesey |
39,44
|
| Midland Island |
Pembrokeshire |
|
| Middle Mouse (Ynys Badrig) |
Anglesey |
|
| Carreg yr Halen |
Anglesey |
|
| North Stack (Ynys Arw) |
Anglesey |
|
| Ramsey (Ynys Dewi) |
Pembrokeshire |
2,58
|
| 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 |
Pembrokeshire |
|
| Shell Island |
Gwynedd |
|
| Skerries (Ynysoedd y Moelrhoniaid) |
Anglesey |
|
| Skokholm (Ynys Sgoc-holm) |
Pembrokeshire |
1,06
|
| Skomer (Ynys Sgomer) |
Pembrokeshire |
2,90
|
| South Stack (Ynys Lawd) |
Anglesey |
|
| Sully Island |
Vale of Glamorgan |
|
| Tusker Rock |
Vale of Glamorgan |
|
| West Mouse (Maen y Bugail) |
Anglesey |
|
| Ynys Bery |
Pembrokeshire |
|
| Ynys Cantwr |
Pembrokeshire |
0,02
|
| Ynys Castell |
Anglesey |
|
| Ynys Dulas |
Anglesey |
|
| Ynys Eilun et Pont yr Eilun |
Pembrokeshire |
0,02
|
| Ynys Faelog |
Anglesey |
0,02
|
| Ynys Feurig |
Anglesey |
|
| Ynys Gaint |
Anglesey |
0,04
|
| Ynys Gifftan |
Gwynedd |
0,07
|
| Ynys Gored Goch |
Anglesey |
|
| Ynys Gwelltog |
Pembrokeshire |
|
| Ynys Lanwol |
Swansea |
0,06
|
| Ynys Llanddwyn |
Anglesey |
|
| Ynys Lochtyn |
Ceredigion |
|
| Ynys Moelfre |
Anglesey |
0,02
|
| Ynys Seiriol |
Anglesey |
0,28
|
| Ynys Tobig |
Anglesey |
|
| Ynys Weiliog |
Anglesey |
|
| Ynys y Bîg |
Anglesey |
|
