Lough Sheelin (from Irish Loch Síodh Linn, meaning "lake of the fairy pool"), in standard Irish Loch Síleann, is a limestone freshwater lough (lake) in Ireland located in County Westmeath, County Meath and County Cavan near the villages of Finnea (also spelled Finea) and Mountnugent and the town of Granard, (County Longford).