Listed below are islands in the Irish Sea which are over 1 km2 in area, or which have a permanent population:
| Name | Area (km2) | Rank (area) | Permanent Population[1] | Rank (pop.) | Country |
|---|---|---|---|---|---|
| Anglesey | 714 | 01 | 69,000 | 02 | Wales |
| Isle of Man[2] | 572 | 02 | 80,056 | 01 | Isle of Man |
| Holy Island | 39 | 03 | 13,579 | 03 | Wales |
| Walney Island[3] | 13 | 04 | 11,388 | 04 | England |
| Lambay Island | 5.54 | 05 | <10 | 08 | Republic of Ireland |
| Bull Island | 3 | 06 | <20 | 07 | Republic of Ireland |
| Bardsey Island | 2.58 | 08 | <5 | 10 | Wales |
| Calf of Man | 2.50 | 09 | 0 | - | Isle of Man |
| Barrow Island | Unknown | - | 2,616 | 05 | England |
| Roa Island | Unknown | - | 100 | 06 | England |
| Ynys Gaint | Unknown | - | <10 | 08 | Wales |
| Piel Island | 0.20 | - | <5 | 10 | England |
| Ynys Castell | Unknown | - | <5 | 10 | Wales |
| Ynys Gored Goch | 0.004 | - | <5 | 10 | Wales |