Belfast North historically had a narrow unionist majority, which gradually decreased over time. The nationalist vote is considerable, and those from a Catholic background (47%) now slightly outnumber those from a Protestant background (46%), according to the 2011 census. It has generated particular interest for a number of highly unusual election results, as well as for several candidates and MPs prominently disagreeing with their parties.
The area saw a steady out movement of Protestants during the Troubles, to some degree replaced by a growing Catholic population, although the overall population of the area fell sharply. However, all the inner-city communities in the constituency are now haemorrhaging electors, and the overall ethnic composition of the constituency now seems stable. The constituency suffered the highest level of violence in Northern Ireland during the Troubles and covers many areas synonymous with the conflict – the New Lodge, Ardoyne, Rathcoole, Ballysillan and Woodvale. The overall tenor of the constituency is working-class, with a high proportion of residents in public housing, and concentrations of low-income single people in the middle Antrim Road and Cliftonville areas. There are some upscale residential areas around Belfast Castle and on the slopes of Cavehill. Sectarian divisions are stark, with a number of Peace lines cutting through the constituency and occasional outbursts of sectarian street violence, and was the focus for post-ceasefire incidents such as the Holy Cross dispute.
The seat was consistently held by the Ulster Unionist Party from its creation until the 1970s. In 1972 the first notable dissent occurred when the sitting MP, Stratton Mills, dissented from the UUP's decision to withdraw from the Conservative whip at Westminster over the suspension of the Stormont Parliament. Mills remained as a Conservative MP, but the following year he joined the Alliance, giving them their only Westminster representation before 2010.
At the 1979 general election, John McQuade of the Democratic Unionist Party won the seat with a mere 27.6% of the vote – the third lowest total for a successful candidate in a UK general election in the twentieth century. This came about due to the strong showing of several other parties, dividing the vote strongly. McQuade also had the distinction of being the oldest person to be initially elected to Westminster in the 20th century. He did not stand at the next general election.
Walker continued to hold the seat until 2001 but gained a reputation for inactivity. In the 2001 general election the DUP contested the seat for the first time since 1983, with their candidate Nigel Dodds campaigning heavily on both their opposition to the Good Friday Agreement and Walker's record. Walker also suffered from a disastrous television interview during the campaign. In the election Walker's vote collapsed to a mere 12%, coming fourth whilst Dodds won the seat. The UUP vote fell even further in both the 2003 Assembly election and the 2005 general election.
Nigel Dodds became the DUP's deputy leader and Commons leader in 2008, but the 2010 general election saw Sinn Féin increase their vote share and reduce the DUP majority. Sinn Féin targeted the seat in the 2015 general election, campaigning on returning the constituency's first Irish nationalist MP and the growing Catholic population surpassing Protestants. However, the DUP and the UUP agreed an electoral pact in which the UUP would withdraw their candidate to help re-elect an unionist. This allowed for Dodds to hold the seat comfortably with an increased majority, although a 4.3% swing to Sinn Féin in the 2017 general election confirmed the seat's marginal status.
Prior to the 2019 general election, the SDLP and UUP withdrew their candidates. In a highly divisive contest marred by threats from loyalist paramilitaries, John Finucane of Sinn Féin won with a majority of 1,943 votes.[3][4][5] This meant that the 2019 election was the first time that Sinn Féin won multiple seats in Belfast and the first time Belfast North had elected a nationalist instead of a unionist. Dodds was replaced as Commons leader by Jeffrey Donaldson.
The city boundaries were expanded under the Belfast Corporation Act 1896. Under the Redistribution of Seats (Ireland) Act 1918, the parliamentary borough was extended to include the whole city and the number of divisions increased from 4 to 9. The Duncairn and Shankill divisions largely replaced the North division.[6][7] These boundaries were in effect at the 1918 general election.
In the parliamentary borough of Belfast, St. Anne's ward (except so much as is comprised in the West division),
so much of Dock ward as is bounded on the south-east by a line drawn along the centre of North Queen Strect, and on the north-east by a line drawn along the centre of New Lodge Road; and on the south-west by a line drawn along the centre of Limestone Road, and continued ina straight line to the centre of York Road, and on the east by 2 line drawn along the centre of Carrickfergus Road,
and in the parish of Shankill, in the county of Antrim, the townlands of:— Ballygomartin, Ballysillan Lower, Greencastle (with the town of Greencastle), Legoniel (with the town of Legoniel), Lowwood, Old Park (with the town of Old Park), and Skegoniell, and so much of the townland of Ballyaghagan as is in the parliamentary borough.[8]
1922–1950
The divisions of Duncairn (Duncairn ward and part of Clifton ward) and Shankill (Shankill ward and the remaining part of Clifton ward).[9]
1950–1974
In the county borough of Belfast, the wards of Duncairn, Shankill and Clifton.[10]
1974–1983
In the county borough of Belfast, the wards of Dock, Duncairn, Clifton and Shankill.[11]
1983–1997
In Belfast, the wards of Ardoyne, Ballysillan, Bellevue, Castleview, Cavehill, Cliftonville, Crumlin, Duncairn, Fortwilliam, Grove, Legoniel, New Lodge, Shankill, and Woodvale.[12]
1997–2010
In Belfast, the wards of Ardoyne, Ballysillan, Bellevue, Castleview, Cavehill, Chichester Park, Cliftonville, Crumlin, Duncairn, Fortwilliam, Legoniel, New Lodge, Water Works, and Woodvale,
and in Newtownabbey, the wards of Abbey, Coole, Dunanney, Valley, and Whitehouse.[13]
2010–2024
In Belfast, the wards of Ardoyne, Ballysillan, Bellevue, Castleview, Cavehill, Chichester Park, Cliftonville, Crumlin, Duncairn, Fortwilliam, Legoniel, New Lodge, Water Works, and Woodvale;
and in Newtownabbey, the wards of Abbey, Ballyhenry, Cloughfern, Collinbridge, Coole, Dunanney, Glebe, Glengormley, Hightown, Valley, and Whitehouse.[14]
2024–
In Antrim and Newtownabbey, the part of the Abbey ward to the south of the northern boundary of the 2008 Belfast North constituency, and the wards of Ballyhenry, Carnmoney Hill, Collinbridge, Glebe, Glengormley, Hightown, O'Neill, Rathcoole, Valley, Whitehouse ward;
and in Belfast, the wards of Ardoyne, Ballysillan, Bellevue, Cavehill, Chichester Park, Cliftonville, Duncairn, Forth River, Fortwilliam, Innisfayle, Legoniel, New Lodge, Water Works.[15]
^"Usual Resident Population". Northern Ireland Neighbourhood Information Service. Northern Ireland Statistics and Research Agency. Archived from the original on 23 September 2021. Retrieved 26 January 2015.
^Uberoi, Elise; Baker, Carl; Cracknell, Richard (19 December 2019). General Election 2019: results and analysis(PDF) (Report). House of Commons Library. Archived(PDF) from the original on 26 January 2020. Retrieved 5 January 2020.