List of parliamentary constituencies in Northern Ireland


is divided into 18 Parliamentary constituencies: 4 borough constituencies in Belfast and 14 county constituencies elsewhere. Section 33 of the Northern Ireland Act 1998 provides that the constituencies for the Northern Ireland Assembly are the same as the constituencies that are used for the United Kingdom Parliament. Parliamentary constituencies are not used for local government, which is instead carried out by 11 district councils; these often have different boundaries.
Each constituency returns one Member of Parliament to the House of Commons at Westminster and five Members of the Legislative Assembly to the devolved Northern Ireland Assembly at Stormont. Six MLAs were returned per constituency until the Assembly Members Act 2016 reduced the number to five, effective from the 2017 Assembly election.

2019 general election

Data from the . For full official results see the .

Historical representation by party

Where a cell is marked → it indicates that the previous MP continued to sit under a new party affiliation. Changes are dated in the header row: either a general election or by-election or change in affiliation.

1801 to 1832 (22 MPs)

Antrim

Londonderry

* Sir George Hill, 2nd Baronet, was elected to sit as MP for both Coleraine and Londonderry City in the 1806 general election and chose to continue to sit for Londonderry City, hence the 1807 by-election, in which Walter Jones was restored to his seat.

Tyrone

* At both the 1802 and 1806 elections, George Knox was returned for both Dungannon and Dublin University and chose to sit for the university seat.

Armagh

* Charles Brownlow was initially elected as a Tory but at some point changed his affiliation to sit with the Whigs.

Down

* The Parliaments of England by Henry Stooks Smith suggests that after the 1806 election there was a petition, which led to Edward Southwell Ruthven being unseated and John Wilson Croker being declared duly elected. Parliamentary Election Results in Ireland, 1801–1922, edited by BM Walker, does not make any reference to such a petition.

Fermanagh

1832 to 1885 (29 MPs)

Antrim

Londonderry

*unseated on petition

Tyrone

Armagh

Down

Fermanagh

1885 to 1918 (25 MPs)

Antrim

Armagh

Belfast

Down

Fermanagh

Londonderry

Tyrone

1918 to 1922 (29 MPs)

1922 to 1950 (13 MPs)

1950 to 1983 (12 MPs)

Periodic boundary reviews commenced in 1947. The elections at which these were implemented are tagged with diamond suit characters, ♦.
The 1st Periodic Review boundary map can be viewed on the . Changes in the 2nd review were relatively minor.
Unionist parties
Nationalist parties
Other

Notes:
  1. The constituency was won by Philip Clarke of Sinn Féin, but he was unseated on petition on the basis that his criminal conviction made him ineligible. Instead, the seat was awarded to the Ulster Unionist Party candidate.
  2. The seat was originally won by Tom Mitchell of Sinn Féin, but Mitchell was subsequently unseated upon petition, on the grounds that his terrorist convictions made him ineligible to sit in Parliament. The seat was awarded to Charles Beattie of the UUP. However, Beattie in turn was also found ineligible to sit due to holding an office of profit under the crown, triggering a further by-election.
  3. Original winner of the 1950 election in that seat, James Godfrey MacManaway, disqualified due to being a clergyman. Teevan won the subsequent by-election

    1983 to present (17, then 18 MPs)

3rd and 4th Review boundary maps can be viewed on the ARK elections website: , .
1Paisley Jr was suspended from the DUP between July and November 2018.

Recent Evolution

Proposed boundary changes

The Boundary Commission for Northern Ireland submitted their final proposals in respect of the Sixth Periodic Review of Westminster Constituencies in September 2018. Although the proposals were immediately laid before Parliament they were not brought forward by the Government for approval. Accordingly, they did not come into effect for the 2019 election which took place on 12 December 2019, and which was contested using the constituency boundaries in place since 2010.
Under the terms of the Parliamentary Voting System and Constituencies Act 2011, the Sixth Review was based on reducing the total number of MPs from 650 to 600 and a strict electoral parity requirement that the electorate of all constituencies should be within a range of 5% either side of the electoral quota.
On 24 March 2020, the Minister of State for the Cabinet Office, Chloe Smith, issued a written statement to Parliament setting out the Government's thinking with regard to parliamentary boundaries. They propose to bring forward primary legislation to remove the statutory obligation to implement the 2018 Boundary Review recommendations, as well as set the framework for future boundary reviews in time for the next review which is due to begin in early 2021 and report no later than October 2023. It is proposed that the number of constituencies now remains at the current level of 650, rather than being reduced to 600, while retaining the requirement that the electorate should be no more than +/- 5% from the electoral quota.