| Inishtooskert | |
| Map: | island of Ireland |
| Native Name: | Inis Tuaisceart |
| Native Name Link: | Irish language |
| Location: | Atlantic Ocean |
| Coordinates: | 52.1305°N -10.5783°W |
| Archipelago: | Blasket Islands |
| Area Acre: | 241 |
| Area Footnotes: | [1] |
| Elevation M: | 226 |
| Country: | Ireland |
| Country Admin Divisions Title: | Province |
| Country Admin Divisions: | Munster |
| Country Admin Divisions Title 1: | County |
| Country Admin Divisions 1: | Kerry |
| Population: | 0 |
Inishtooskert (sometimes spelled Inishtooshkert[2]) (Inis Tuaisceart in Irish) is the northernmost of the Blasket Islands, County Kerry, Ireland.
The Irish name means "northern island" and the English name is a phonetic spelling of the Irish name. The island is also known as An Fear Marbh (the dead man) or the sleeping giant due to its appearance when seen from the east (as in the photograph).[3]
Inishtooskert holds important seabird colonies, as well as extensive ruins of ancient stone buildings.
Of particular note is the colony of European storm-petrels. With over 27,000 pairs in 2000 (Seabird 2000 survey), this is the largest colony in Ireland.
The island appears frequently in David Lean's 1970 film Ryan's Daughter.