Northern Ireland is the smallest of the four parts of the United Kingdom in terms of both area and population, containing 2.9% of the total population and 5.7% of the total area of the United Kingdom. It is the smaller of the two political entities on the island of Ireland by area and population, the other being the Republic of Ireland. Northern Ireland contains 27.1% of the total population and 16.75% of the total area of the island of Ireland.

The Belfast Metropolitan Area dominates in population terms, with over a third of the inhabitants of Northern Ireland.

When Northern Ireland was created, it had a Protestant majority of approximately two-to-one, unlike the Republic of Ireland, where Catholics were in the majority. The 2001 census was the first to show that the Protestant and other (non-Catholic) Christian share of the population had dropped below 50%, but 53.1% still identified as being from a Protestant or other Christian background. In the 2011 census, this dropped to 48.4%. In 2021, the recorded number of Catholics by background (45.7%) overtook the Protestant and other Christian by background share (43.48%), becoming the plurality, with no group in the overall majority.

Its people speak Ulster English which is itself heavily influenced by the Scots language of which Ulster Scots is a dialect, while a significant number speak Irish (Gaelic) or Ulster Scots. In addition the Ulster dialect of Irish (Gaelic) also has a closer connection to Scottish Gaelic than other Irish (Gaelic) dialects. This is both because of historic links with Scotland going back centuries, and because of settlements of lowland Scots Protestants in Ulster in the 17th century, such as the Plantation of Ulster.

Also unlike the Republic, a large proportion of people in Northern Ireland have a British national identity, although a significant minority identifies as Irish. Many people in Northern Ireland have a Northern Irish identity, whether in addition to a British or Irish identity or by itself.

Northern Ireland has the smallest proportion of people from minority ethnic (non-white) backgrounds of any part of the UK, with 3.4% of the population being from a minority ethnic group, compared to 18.3% in England and Wales and 12.9% in Scotland.

Historic population trends

Cities and towns by populationBelfast

Derry#SettlementPopulationMetro populationLisburn

Newry1Belfast293,300626,3392Derry85,27994,3763Lisburn Part of Belfast metropolitan area51,44784,0904Craigavon Urban Area72,3015Metropolitan Newtonabbey 67,5996Bangor 64,5967Metropolitan Castlereagh 58,7628Ballymena31,2059Newtownards29,67710Newry28,53011Carrickfergus 28,141

Fertility

Population density

Northern Ireland's population density is 133 people per square kilometre – comparable to European countries such as Denmark and the Czech Republic. If Northern Ireland were a sovereign state, it would have the 16th-highest population density in Europe. It has a higher population density than Scotland (70 people per km2), but less than England (434 per km2) and Wales (153 per km2).

Belfast is the most population-dense of the 11 local government districts at 2,617 per km2, with the highest population (345,418) and least land area (133 km2) of any district, and includes both Belfast City and much of the Metropolitan Castlereagh settlement (formerly part of the Castlereagh local government district before 2015).

Fermanagh and Omagh is the least dense district, with the lowest population (116,812) and greatest land area (2,836 km2). It includes all of Northern Ireland's least-populous county, Fermanagh (except the townland of Killybane near Fivemiletown), and the largely rural former Omagh district.

Of the 80 District Electoral Areas that make up the local government districts, Botanic in Belfast has the highest population density at 4,653 people per km2, as well as being the most populous DEA (49,727 people in 2021). The DEA includes Belfast city centre, Queen's University, and much of the city's student population.

Erne West in Fermanagh and Omagh has the lowest population density of any DEA, with 20 people per km2, as well as being the least populous DEA (14,661 people in 2021). Erne West is largely mountainous and separated from the rest of Northern Ireland by Lough Erne, with only a few roads around and over the lough. The largest settlement, Bellanaleck, a small village near Enniskillen, is home to only 714 people, and is apart from the other small villages spread through Erne West's large, narrow area.

As of 2021, 50.2% of Northern Ireland's population lived in the 217 most population-dense electoral wards (around 47% of Northern Ireland's 462 wards). The 217 wards have an area of 460.1 km2, 3.3% of Northern Ireland's total area. Of these 217 wards, 99 are a contiguous area covering most of Belfast, Castlereagh, Lisburn and Newtownabbey. These 217 wards are highlighted in red on the map.

These wards cover part or all of the 28 largest settlements in Northern Ireland, as well as Warrenpoint, Donaghadee, Ballynahinch, Moira, Maghera and Coalisland. The vast majority of these wards contain or are near a motorway, dual carriageway or train station. Considering this, the most remote wards are the Portora and Erne wards in Ennskillen, which are 30 miles from the A4 dual carriageway near Ballygawley.

Furthermore, 50.02% of Northern Ireland's population lived in the most population-dense contiguous area of 216 electoral wards. These 216 wards have an area of 1,299 km2, 9.4% of Northern Ireland's total area. These 216 wards are highlighted in purple on the map. These wards cover part or all of the 10 largest settlements, and almost entirely track Northern Ireland's rail lines, motorways and dual carriageways. The exceptions are a spur towards Armagh city; and a string of villages between Ballymena and Limavady.

The electoral wards in Northern Ireland with the highest and lowest population density are listed in the table below:

No.Electoral Ward (2012)District Electoral Area (2012)Local Government District (2012)Electoral Ward population (2021)Density (/km2)Area (km2)1ArdoyneOldparkBelfast5,49010,235.660.542WoodstockTitanicBelfast6,4319,649.750.673WindsorBotanicBelfast11,3028,183.801.384ClonardCourtBelfast5,9997,641.160.795BloomfieldTitanicBelfast5,8947,224.940.826BeersbridgeTitanicBelfast6,6106,952.380.957New LodgeOldparkBelfast4,8816,815.490.728ConnswaterTitanicBelfast5,9296,387.940.939BallymurphyBlack MountainBelfast5,1316,329.390.8110BeechmountBlack MountainBelfast5,3946,255.170.8611WoodvaleCourtBelfast5,1706,143.260.8412BallymacarrettTitanicBelfast5,9055,972.050.9913ShankillCourtBelfast6,4455,793.761.1114FairviewThree Mile WaterAntrim and Newtownabbey3,1155,610.430.5615CentralBotanicBelfast15,4465,497.582.8116CregaghLisnasharraghBelfast4,5875,418.460.8517FortwilliamCastleBelfast4,7175,381.770.8818ShantallowBallyarnettDerry City and Strabane3,6675,317.610.6919SilverstreamBangor WestArds and North Down3,9605,305.380.7520RosettaLisnasharraghBelfast5,7935,215.151.11.....................443DerrylinErne WestFermanagh and Omagh2,79426.45105.65444DunnamanaghSperrinDerry City and Strabane3,51325.75136.45445Fairy WaterWest TyroneFermanagh and Omagh2,82625.57110.50446Boho, Cleenish and LetterbreenErne WestFermanagh and Omagh3,46624.76139.99447DungivenBenbradaghCauseway Coast and Glens3,29724.44134.88448RossleaErne EastFermanagh and Omagh2,33124.4395.43449MagilliganLimavadyCauseway Coast and Glens3,48124.00145.01450DonaghErne EastFermanagh and Omagh2,52723.17109.06451FivemiletownClogher ValleyMid Ulster3,17421.34148.76452BrookeboroughErne EastFermanagh and Omagh2,57920.88123.50453DrumquinWest TyroneFermanagh and Omagh2,91018.38158.31454DerrygonnellyErne WestFermanagh and Omagh2,89818.00160.98455SlemishBraidMid and East Antrim3,20717.90179.17456Florence Court and KinawleyErne WestFermanagh and Omagh2,88317.61163.75457Belleek and BoaErne NorthFermanagh and Omagh3,12315.94195.90458GlendergDergDerry City and Strabane3,20015.09212.05459OwenkillewMid TyroneFermanagh and Omagh2,69814.40187.30460Torr Head and RathlinThe GlensCauseway Coast and Glens3,59714.21253.11461Glenelly ValleySperrinDerry City and Strabane3,40313.25256.90462Belcoo and GarrisonErne WestFermanagh and Omagh2,64413.07202.26

Place of birth

In 2001, 91.0% of the population were born in Northern Ireland, 7.2% were born in other parts of the UK and Ireland, and 1.8% were born elsewhere. By 2021, the proportion of immigrants from outside the UK and Ireland had risen to 6.6%, while the proportion born within other parts of the UK and Ireland had fallen to 6.9%. The highest number of non-British/Irish immigrants are in Belfast City Council, followed by Armagh City, Banbridge and Craigavon Borough Council and Mid Ulster District Council. The town of Dungannon in Mid Ulster District Council has a bigger share of immigrants than any town in Northern Ireland, while Derry City and Strabane has the smallest share of immigrants.

Place of Birth200120112021 Number % Number %Number% Northern Ireland 1,534,268 91.04 1,608,853 88.841,646,27686.50% England 61,609 3.66 64,717 3.5772,9403.83% Scotland 16,772 1.00 15,455 0.8516,5210.87% Wales 3,008 0.18 2,552 0.142,7960.15% Republic of Ireland 39,051 2.32 37,833 2.0940,3572.12% Other European Union member countries 10,355 0.61 67,4513.54% — Member countries prior to 2004 expansion 9,703 0.54 — Accession countries 2004 onwards 35,704 1.97 Other outside the EU 20,204 1.20 36,046 1.99 57,0122.99% Europe3,6890.19%Africa10,7610.57%Middle East and Asia29,2411.54%North, Central America and Caribbean8,2070.43%South America1,8580.10%Oceania and other3,0760.16% Total 1,685,267 100.00 1,810,863 100.001,903,173100%

Below are the 5 largest foreign-born groups in Northern Ireland according to 2014 ONS estimates. Figures given are the central estimates. See the source for 95 per cent confidence intervals.

Country of birthEstimated population, 2013Estimated population, 2014Estimated population, 2015PolandLithuaniaIndiaPhilippines

Emigration Detailed statistic on births are available between 1887 and 2022 in Birth tables and deaths between 1955 and 2022 in Death tables

Using deaths and births between 1955 and 2021, and the number of those from the 2021 census whose country of birth is Northern Ireland, we can estimate emigration for those aged under 66 by subtracting the total of the number of deaths and the number of those born in Northern Ireland who are still living there.

+ Northern Irish emigration estimates All ages 18-66 year olds Births 1955-2021 1,801,552 1,353,624 Deaths 1955-2021 among those born 1955-2021 78,914 76,226 Country of birth is Northern Ireland in 2021 Census, ages 0–66 1,389,081 965,538 Estimated Emigration 333,557 311,860 Estimated Emigration as a percentage of births 18.5% 23.0%

This gives an estimate of 18.5% of all people born since 1955 have emigrated, or 23% of adults aged 18–66. This is an estimate of the minimum amount of emigration, since deaths are not broken down by country of birth, so some of those will not have been born in Northern Ireland. Most deaths occur in the over 50 and currently about 12.5% of those aged 50 and over were born outside Northern Ireland. Adjusting the number of deaths downwards by 12.5%, we can estimate an emigration rate of 18.5 to 19% for all ages, and 23.0% to 23.7% for adults aged 18–66.

Doing the same analysis by age shows that this is consistent with the actual number of those born in Northern Ireland from the 2021 England/Wales census, where about 40% of emigrants have settled in England or Wales.

Below are the numbers of Northern Ireland born living outside Northern Ireland from the most recent censuses for England, Wales, Scotland, Ireland, Australia, and New Zealand.