Voici une liste des îles appartenant au Pays de Galles.
| Name | Island Group / Location |
|---|---|
| Anglesey | Mer d'Irlande |
| Barry Island | Canal de Bristol |
| Caldey Island | Pembrokeshire |
| Cardigan Island | Ceredigion |
| Church Island | Anglesey |
| Cribinau | Anglesey |
| East Mouse | Anglesey |
| Flat Holm | Canal de Bristol |
| Gateholm | Pembrokeshire |
| Grassholm | Pembrokeshire |
| Holy Island, Anglesey | Anglesey |
| Midland Island | Pembrokeshire |
| Middle Mouse | Anglesey |
| North Stack | 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 |
| Shell Island | Gwynedd |
| The Skerries | Anglesey |
| Skokholm Island | Pembrokeshire |
| Skomer Island | Pembrokeshire |
| South Stack | Anglesey |
| Sully Island | Vale of Glamorgan |
| Tusker Rock | Vale of Glamorgan |
| West Mouse | Anglesey |
| Ynys Bery | Pembrokeshire |
| Ynys Cantwr | Pembrokeshire |
| Ynys Castell | Anglesey |
| Ynys Dulas | Anglesey |
| Ynys Eilun et Pont yr Eilun | Pembrokeshire |
| Ynys Enlli | Gwynedd |
| Ynys Faelog | Anglesey |
| Ynys Feurig | Anglesey |
| Ynys Gaint | Anglesey |
| Ynys Gored Goch | Anglesey |
| Ynys Gwelltog | Pembrokeshire |
| Ynys Llanddwyn | Anglesey |
| Ynys Lochtyn | Ceredigion |
| Ynys Moelfre | Anglesey |
| Ynys Seiriol | Anglesey |
| Ynys Weiliog | Anglesey |
| Ynys y Bîg | Anglesey |
| Island | Area (sq mi) | Area (km²) | |
| 1 | Anglesey | 275.60 | 713.80 |
| 2 | Holy Island | 15.22 | 39.44 |
| 3 | Skomer Island | 1.12 | 2.90 |
| 4 | Ramsey Island | 0.99 | 2.58 |
| 5 | Caldey Island | 0.84 | 2.18 |
| 6 | Ynys Enlli | 0.76 | 1.99 |
| 7 | Skokholm | 0.41 | 1.06 |
| 8 | Flat Holm | 0.13 | 0.33 |
| 9 | Ynys Seiriol | 0.11 | 0.28 |
| 10 | Cardigan Island | 0.06 | 0.15 |