Achonry is a village in County Sligo, Ireland. The old name is Achad Cain Conairi. St. Nath Í ua hEadhra (O'Hara) founded a monastery here. The foundation gave the later diocese its name. The monastery was founded on land granted by the Clan Conaire. Nath Í was the teacher of St. Féichín of Ballysadare.
The diocese was co-extensive with the barony of Leyney (Luighne).
In the parish is the former Church of Ireland Cathedral of St Crumnathy, now deconsecrated.
see Bishop of Achonry.