Credit:  The majority of the following information was obtained from http://www.ireland.com/.  Please visit http://www.ireland.com/ for more details.

Irish Administrative divisions

Province: There are four provinces in Ireland, Ulster (9 counties), Connacht (5 counties), Munster (6 counties) and Leinster (12 counties).

County: The County is the principal unit of local Government. There are 32 counties in Ireland, 26 in the Republic of Ireland and 6 in Northern Ireland, varying greatly in size and population. Generally speaking, they are much larger and more populous than American counties.  The counties exists as follows:

 

Ulster:

Antrim, Armagh, Cavan, Derry, Donegal, Down, Fermanagh, Monaghan, Tyrone.

 

Connaught:

Galway, Leitrim, Mayo, Roscommon, Sligo

 

Munster:

Clare, Cork, Kerry, Limerick, Tipperary, Waterford.

 

Leinster:

Carlow, Dublin, Kildare, Kilkenny, Laois, Longford, Louth, Meath, Offaly, Westmeath, Wexford, Wicklow

Barony:

A Barony is an important county subdivision.

It is thought to be a Norman division although it's precise origin is unknown.

There are generally between seven and ten baronies per county although Cork has twenty and Louth has only four.

A barony can occupy parts of two counties in which case it is referred to as half a barony.

There are 331 baronies in Ireland. 

Up to the end of the nineteenth century, counties were subdivided into baronies, although they were not much used for administrative purposes and thus figure little in the records relevant to genealogical research.

There were about 325 baronies in the country.

 

Poor Law Union:

The Poor Law Act of 1838 introduced another administrative division - The Poor Law Union.

Initially there were 130 and eventually 163 Poor Law Unions. Between 1838 and 1852, 163 workhouses were built throughout the country, each at the centre of an area known as a Poor Law Union.

The workhouses were normally situated in a large market town, and the Poor Law Union comprised the town and its catchment area, with the result that the Unions in many cases ignored the existing boundaries of parish and county.

The workhouse in the town provided relief for the unemployed and destitute,
generally under very harsh conditions.

Records were kept of the inmates and these can provide useful research material.  These were the catchment areas of the workhouses set up from the 1830s on to try to deal with the most destitute.

They became the bases of the registration districts used for state records of births, marriages and deaths. 

 

Civil Parish:

There are 2508 Civil Parishes in Ireland.

They were originally ecclesiastical divisions and they often break both county and barony, boundaries.

They became important civil divisions in their own right. 

Civil parishes were the original units of administration of the medieval church in Ireland and were used right up to the end of the nineteenth century for local and central government.

Because of this, they are extremely important for Irish genealogy, providing, for example, the only means of connecting a placename to the Roman Catholic records which cover it.

Gen.ie uses the civil parish to connect localities to the records which relate to them.

 

Townland:

There are 60,462 townlands in Ireland (65,000 recorded in the 1851 Townlands Index). 

 It is the smallest administrative division (i.e. smallest officially recognized geographical unit in rural Ireland) and on average covers about 350 acres (varying in size from a few acres to several thousand). 

Many Townlands share the same name - for example there are 56 Kilmores and 47 Dromores.

 

Dispensary District:

Poor Law Unions were subdivided into dispensary districts following the 1851 Medical Charities Act.

 

Superintendent Registrar's District:

Poor Law Unions became known as Superintendent Registrar's districts in order to record births, marriages and deaths as a result of the 1863 Acts for the Registration of Births, Deaths and Marriages.



Registrar's District:

Dispensary Districts became known as Registrar's districts in order to record births, deaths and marriages as a result of the 1863 Acts for the Registration of Births, Deaths and Marriages.



Diocese:

This is a large ecclesiastical division.

There are 22 dioceses which in turn form part of 4 archdioceses.

These are similar to the four provinces of Ireland.



Parish:

A diocese is subdivided into parishes.

Parishes are usually composed of the aforementioned civil parishes.

However, modern Catholic parishes do not follow this general rule.