Map - County Mayo (Mayo County)

County Mayo (Contae Mhaigh Eo, meaning "Plain of the yew trees") is a county in Ireland. In the West of Ireland, in the province of Connacht, it is named after the village of Mayo, now generally known as Mayo Abbey. Mayo County Council is the local authority. The population was 137,231 at the 2022 census. The boundaries of the county, which was formed in 1585, reflect the Mac William Íochtar lordship at that time.

It is bounded on the north and west by the Atlantic Ocean; on the south by County Galway; on the east by County Roscommon; and on the northeast by County Sligo. Mayo is the third-largest of Ireland's 32 counties in area and 18th largest in terms of population. It is the second-largest of Connacht's five counties in both size and population. Mayo has 1168 km of coastline, or approximately 21% of the total coastline of the State. It is one of three counties which claims to have the longest coastline in Ireland, alongside Cork and Donegal. There is a distinct geological difference between the west and the east of the county. The west consists largely of poor subsoils and is covered with large areas of extensive Atlantic blanket bog, whereas the east is largely a limestone landscape. Agricultural land is therefore more productive in the east than in the west.

* The highest point in Mayo (and Connacht) is Mweelrea, at 814 m

* The River Moy in the northeast of the county is renowned for its salmon fishing

* Ireland's largest island, Achill Island, lies off Mayo's west coast

* Mayo has Ireland's highest cliffs at Croaghaun, Achill Island, while the Benwee Head cliffs in Kilcommon Erris drop almost perpendicularly 900 ft into the Atlantic Ocean.

* The northwest areas of County Mayo have some of the best renewable energy resources in Europe, if not the world, in terms of wind resources, ocean wave, tidal and hydroelectric resources

There are nine historic baronies, four in the northern area and five in the south of the county:

North Mayo

* Erris (north-west, containing Belmullet, Gweesalia, Bangor Erris, Kilcommon, Ballycroy etc.)