Civil parishes are units of territory in the island of Ireland that have their origins in old Gaelic territorial divisions. They were adopted by the Anglo-Norman Lordship of Ireland and then by the Elizabethan Kingdom of Ireland, and were formalised as land divisions at the time of the Plantations of Ireland. They no longer correspond to the boundaries of Roman Catholic or Church of Ireland parishes, which are generally larger. Their use as administrative units was gradually replaced by Poor Law Divisions in the 19th century, although they were not formally abolished. Today they are still sometimes used for legal purposes, such as to locate property in deeds of property registered between 1833 and 1946.

A townland is a small geographical division of land, historically and currently used in Ireland and in the Western Isles in Scotland, typically covering 100–500 acres (40–202 ha). The townland system is of Gaelic origin, antedating the Norman invasion, and most have names of Irish origin. However, some townland names and boundaries come from Norman manors, plantation divisions, or later creations of the Ordnance Survey. The total number of inhabited townlands in Ireland was 60,679 in 1911. The total number recognised by the Irish Place Names database as of 2014 was 61,098, including uninhabited townlands, mainly small islands.