List of United Kingdom Parliament constituencies in Ireland and Northern Ireland

Ireland became part of the United Kingdom under the Act of Union 1800 from 1 January 1801.

The electoral effect of the Act of Union 1800

Under the Act of Union 1800, Ireland was divided into constituencies for elections to the United Kingdom Parliament.

In 1801, the thirty-two counties continued to return two MPs as they had in the former Parliament of Ireland. Cork City and Dublin City also retained two seats. The larger Boroughs and Dublin University were reduced to one seat. Some of the smaller Irish Boroughs lost separate representation in the new Parliament.

The electoral effect of partition 1918-1922

The general election of 1918 (in Ireland) was, in British law, to fill the 105 Irish seats in the UK House of Commons for the 31st United Kingdom Parliament. In practice only the non Sinn Féin MPs took their seats at Westminster. This Parliament first met on 4 February 1919 and was dissolved on 26 October 1922. At its dissolution the Parliamentary seats in the twenty six counties comprising the Irish Free State were abolished.

Irish Republicans regard the 1918 election as being to the First Dáil. In practice only the Sinn Féin Members of Parliament refused to take their seats in the House of Commons and became Teachtaí Dála in the new revolutionary assembly. See list of members of the 1st Dáil. The initial meeting of the First Dáil was on 21 January 1919 and it last met on 10 May 1921.

From the United Kingdom general election, 1922, only the six counties of Northern Ireland were represented in Parliament.

Summary of constituencies and Members of Parliament

Key to categories: BC - Borough constituencies, CC - County constituencies, UC - University constituencies, Total C - Total constituencies, BMP - Borough Members of Parliament, CMP - County Members of Parliament, UMP - University Members of Parliament.

Notes

1801-1832 In cases where both a borough and county area have the same name and seats of each type exist simultaneously Borough, City or County (as appropriate) are included in the constituency name in the list below, unless there is a later county seat of the same name in which case County is omitted. Borough constituencies: 2 two member, 31 single member; seats 35. University constituency: 1 single member seat. County constituencies: 32 two member; seats 64. Constituencies: 66. Members of Parliament: 100.

1832-1870 Except for some minor boundary changes in 1832 and 1868, the 66 constituencies were unchanged. Belfast, Galway Borough, Limerick City, Waterford City and Dublin University gained a second seat. Borough constituencies: 6 two member, 27 single member; seats 39. University constituency: 1 two member; seats 2. County constituencies: 32 two member; seats 64. Constituencies: 66. Members of Parliament: 105.

1870-1885 Cashel and Sligo Borough were disenfranchised for corruption in 1870. Borough constituencies: 6 two member, 25 single member; seats 37. University constituency: 1 two member; seats 2. County constituencies: 32 two member; seats 64. Constituencies: 64. Members of Parliament: 103.

1885-1918 There was a redistribution of constituencies. All seats were single member, except for Cork City and Dublin University, which continued to return two members. Divisions of a borough or county are given in the list below with the name of the borough or county preceding the name of the division. County division compass point names normally have the direction before the county name i.e. East Antrim. The list below treats such names like the borough equivalents, with the name of the place preceding the compass point, i.e. Antrim East. Borough constituencies: 1 two member, 14 single member; seats 16. University constituency: 1 two member; seats 2. County constituencies: 85 single member seats. Constituencies: 101. Members of Parliament: 103.

1918-1922 There was a redistribution of constituencies. All seats were single member, except for Cork City and Dublin University, which continued to return two members. From 1918 some former constituency names are revived. Such seats are identified by using (1) or (2) after the constituency name. Borough constituencies: 1 two member, 19 single member; seats 21. University constituencies: 1 two member, 2 single member; seats 4. County constituencies: 80 single member seats. Constituencies: 103. Members of Parliament: 105.

1922-1950 There was a redistribution of constituencies, following the Anglo-Irish Treaty and the establishment of the Irish Free State. Twenty-six of the thirty-two Irish counties ceased to be represented in the United Kingdom Parliament. The remaining six counties formed Northern Ireland. All seats were single member, except for Antrim, Down and Fermanagh & Tyrone. Those three seats elected two members each. Some seats included parts of more than one county. The predominant county when the constituency is created is named in those cases. Borough constituencies: 4 single member seats. University constituency: 1 single member seat. County constituencies: 3 two member, 2 single member; seats 8. Constituencies: 10. Members of Parliament: 13.

1950-1983 There was a redistribution of constituencies. All seats were single member ones from this time. Borough constituencies: 4 single member seats. County constituencies: 8 single member seats. Constituencies and Members of Parliament: 12.

1983-1997 There was a redistribution of constituencies. The historic counties ceased to be relevant to constituency boundaries. Seats first created from 1983 are not allocated to a county. Borough constituencies: 4 single member seats. County constituencies: 13 single member seats. Constituencies and Members of Parliament: 17.

From 1997 There was a redistribution of constituencies. Borough constituencies: 4 single member seats. County constituencies: 14 single member seats. Constituencies and Members of Parliament: 18.

List of constituencies during the Union with Great Britain

List of Northern Ireland constituencies

Sources

• See List of former United Kingdom Parliamentary constituencies
• Parliamentary Election Results in Ireland, 1801-1922, edited by B.M. Walker (Royal Irish Academy 1978)