This dataset provides Census 2021 estimates for the number of usual residents in Northern Ireland. The dataset also shows the population density, as well as the size of the geographical area. The estimates and area boundaries are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

To find out how Data Zones and Super Data Zones have been developed, and how other Northern Ireland geographies can be approximated, please read the notes here

The quality assurance report can be found here

The 2021 Northern Ireland Census marked the first time since records began where the Catholic share of the population was larger than the combined Protestant share. In 2021, over 42 percent of the population classified themselves as Catholic or from a Catholic background, in comparison with 37 percent classified as Protestant or from a Protestant background. Additionally, the share of the population with no religion (or those who did not answer) was 19 percent; larger than any individual Protestant denomination. This marks a significant shift in demographic and societal trends over the past century, as Protestants outnumbered Catholics by roughly 2:1 when Northern Ireland was established in the 1920s. Given the Catholic community's historic tendency to be in favor of a united Ireland, many look to the changing religious composition of the population when assessing the potential for Irish reunification. Religion's historical influence A major development in the history of British rule in ireland was the Plantation of Ulster in the 1600s, where much of the land in the north (historically the most rebellious region) was seized from Irish Catholics and given to Protestant settlers from Britain (predominantly Scots). This helped establish Protestant dominance in the north, created a large section of the population loyal to the British crown, and saw a distinct Ulster-Scots identity develop over time. In the 1920s, the republican movement won independence for 26 of Ireland's 32 counties, however, the six counties in Ulster with the largest Protestant populations remained part of the UK, as Northern Ireland. Following partition, structural inequalities between Northern Ireland's Protestant and Catholic communities meant that the Protestant population was generally wealthier, better educated, more politically empowered, and had better access to housing, among other advantages. In the 1960s, a civil rights movement then emerged for equal rights and status for both sides of the population, but this quickly turned violent and escalated into a the three-decade long conflict now known as the Troubles.

The Troubles was largely fought between nationalist/republican paramilitaries (mostly Catholic), unionist/loyalist paramilitaries (mostly Protestant), and British security forces (including the police). This is often described as a religious conflict, however it is more accurately described as an ethnic and political conflict, where the Catholic community generally favored Northern Ireland's reunification with the rest of the island, while the Protestant community wished to remain in the UK. Paramilitaries had a large amount of support from their respective communities in the early years of the Troubles, but this waned as the conflict progressed into the 1980s and 1990s. Demographic and societal trends influenced the religious composition of Northern Ireland's population in these decades, as the Catholic community had higher fertility rates than Protestant communities, while the growing secularism has coincided with a decline in those identifying as Protestant - the dip in those identifying as Catholic in the 1970s and 1980s was due to a protest and boycott of the Census. The Troubles came to an end in 1998, and divisions between both sides of the community have drastically fallen, although they have not disappeared completely.

These statistics contain the first results from Census 2021, and provide estimates of the Northern Ireland population by five-year age band and sex, residence type, and the household count with average household size.

Estimates in this release were published in rounded form.

This table provides Census 2021 estimates that classify people by National identity (8 categories) by Religion (8 categories) for Northern Ireland. The table contains 64 counts.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

'Religion' indicates religion, religious denomination or body. 'Catholic' includes those who gave their current religion as Catholic or Roman Catholic.

Quality assurance report can be found here

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by ethnic group.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

This table reports the categories for which there are 10 or more usual residents. Where there are fewer than 10 usual residents for any category, these have been reported in a residual group which may or may not contain 10 or more usual residents in total.

All ethnic groups are classified within one of the five groups: White, Asian, Black, Mixed, and Other. 'Irish Traveller' is included in 'Other'; this is changed from Census 2011 when 'Irish Traveller' was included in 'White'.

Quality assurance report can be found here

The population of Northern Ireland was 1.93 million people in 2024, compared with 1.84 million ten years earlier in 2013. Since 1971, the population of Northern Ireland has increased by approximately 387,500 people.

This dataset provides Census 2021 estimates that classify households in Northern Ireland, with at least one usual resident, by household size. It also includes an estimate of the number of usual residents living in households and average household size. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

Average household size is a calculation of the usually resident population living in households divided by the number of households.

The quality assurance report can be found here

Between 1821 and 1921, the entire island of Ireland was a part of the United Kingdom of Great Britain and Ireland, after both islands were united by the Act of Union in 1800. This graph shows only the population of the six counties of Ireland that would go on to become Northern Ireland. The population was just under 1.4 million in 1821 and grew to 1.7 million in the next twenty years.

Between 1845 and 1849 the Great Famine devastated the overall population of Ireland, causing the deaths of approximately one million people, and causing a further million to emigrate. Although the famine affected the population of the west and south of Ireland much more severely than the north, the population of the six counties still fell by over 200,000 people between 1841 and 1851. The population then continued to fall, reaching it's lowest point in the 1890s where it was 1.2 million. The Northern Irish population then grows slowly until the mid to late 1900s, during which time the state of Northern Ireland was founded in 1921. The population the reaches over 1.54 million in the 1960s, before it falls again in the 1970s. This drop in population coincides with the outbreak and the most violent decade of the Troubles in Northern Ireland, which was a conflict that dominated Northern Irish daily life for decades. However, from 1981 onwards the population grows by 70,000 to 12,000 every ten years, surpassing it's pre-famine level in the 1990s.

National and subnational mid-year population estimates for the UK and its constituent countries by administrative area, age and sex (including components of population change, median age and population density).

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by ethnic group, and by broad age bands. The estimates are as at census day, 21 March 2021.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

The ethnic groups reported are those for which there was a tick-box on the census questionnaire, plus any ethnic group with more counts than the smallest tick-box.

'Age' is age at last birthday.

Quality assurance report can be found here

In 2021, there were **** births per 1,000 people in Northern Ireland, compared with eleven in the previous year. Between 2000 and 2008, Northern Ireland's birth rate increased from **** to **** but started to decline gradually until 2012 when it dropped from **** to **** in just one year. During this provided time period, the birth rate in Northern Ireland was highest in 1971, when it was **** and was at its lowest in 2020 when there were just eleven births per 1,000 people. Falling birth rates in the UK For the United Kingdom as a whole, the birth rate fell to **** births per 1,000 people in 2020, before a slight uptick to **** in 2021. After a postwar peak of **** births per 1,000 people in 1964, the UK birth rate fell sharply to just **** by 1977. Between 1977 and 2012 the birth rate fluctuated between **** and ****, but declined in every year between 2012 and 2020. In 2021, the UK's fertility rate (the number of births per women) fell to just ****, compared with **** in 1964. Since 1973, the UK has fallen below the minimum replacement level fertility rate of ***, and without immigration would likely see its population decline in the long term. Global demographic trends The considerable decline in the UK's fertility rate in recent decades is not an isolated phenomenon. As of 2025, Africa was, at ****, the only continent to have a fertility rate higher than the global average of ****. Several countries, mainly in East Asia and Europe, have far lower fertility rates than the UK or the global average, however. South Korea provides the most dramatic example of this trend, with its fertility rate falling from **** in 1960 to just **** by 2020. By the *****, it is expected that, as Africa's fertility rate converges with the rest of the world, the global population will peak at around **** billion and start to decline.

This dataset provides Census 2021 estimates that classify usual residents in Northern Ireland by their religion, and by broad age bands.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

'Religion' indicates religion, religious denomination or body.

'Age' is age at last birthday.

'Catholic' includes those who gave their current religion as Catholic or Roman Catholic.

Quality assurance report can be found here

This table provides Census 2021 estimates that classify people by Country of birth (12 categories) by Religion or religion brought up in for Northern Ireland. The table contains 48 counts.

The census collected information on the usually resident population of Northern Ireland on census day (21 March 2021). Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on census day. Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc. The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.

notes

1. 'EU' is the European Union and is as defined on census day (21 March 2021).
2. People who gave 'Cyprus' as their country of birth are included within the 'Europe: Other EU countries' category.
3. 'Europe: Other Non-EU countries' includes United Kingdom (part not specified) and Ireland (part not specified).
4. 'Religion' indicates religion, religious denomination or body.
5. 'Catholic' includes those who gave their current religion as Catholic or Roman Catholic.

Quality assurance report can be found here

Description of Data Population estimates for the 3,780 Data Zones in Northern Ireland were published on 29th May 2025. Time Period Estimates are provided for mid-2021 to mid-2023. Notes: 1. Estimated populations are given as of 30th June for the year noted, rounded to the nearest person. 2. Rounding for estimates at this geographic level is independent. As such, figures may not add to higher geography totals. Methodology The population estimates for small geographical areas are created from an average of two statistical methods: the ratio change and cohort-component methods. The ratio change method applies the change in secondary (typically administrative) data sources to Census estimates. The 2023 small geographical area estimates use a single statistical dataset which has been created by amalgamating a series of different administrative data sources. This statistical dataset is a de-duplicated admin based estimate for the usually resident population of NI. The cohort-component method updates the Census estimates by ‘ageing on’ populations and applying information on births, deaths and migration. An average of both methods is taken and constrained to the published population figures. Further information is available at: NISRA 2023 Mid-year Population Estimates webpage Geographic Referencing Population Estimates are based on a large number of secondary datasets. Where the full address was available, the Pointer Address database was used to allocate a unique property reference number (UPRN) and geo-spatial co-ordinates to each home address. These can then be used to map the address to particular geographies. Where it was not possible to assign a unique property reference number to an address using the Pointer database, or where the secondary dataset contained only postcode information, the Central Postcode Directory was used to map home address postcodes to higher geographies. A small proportion of records with unknown geography were apportioned based on the spatial characteristics of known records. Further Information The next estimates of the population for Northern Ireland will be released later in 2025. Contact: NISRA Customer Services 02890 255156 census@nisra.gov.uk Responsible Statistician: Shauna Dunlop

This dataset contains gridded human population with a spatial resolution of 1 km x 1 km for the UK based on Census 2021 (Census 2022 for Scotland) and Land Cover Map 2021 input data. Data on population distribution for the United Kingdom is available from statistical offices in England, Wales, Northern Ireland and Scotland and provided to the public e.g. via the Office for National Statistics (ONS). Population data is typically provided in tabular form or, based on a range of different geographical units, in file types for geographical information systems (GIS), for instance as ESRI Shapefiles. The geographical units reflect administrative boundaries at different levels of detail, from Devolved Administration to Output Areas (OA), wards or intermediate geographies. While the presentation of data on the level of these geographical units is useful for statistical purposes, accounting for spatial variability for instance of environmental determinants of public health requires a more spatially homogeneous population distribution. For this purpose, the dataset presented here combines 2021/2022 UK Census population data on Output Area level with Land Cover Map 2021 land-use classes 'urban' and 'suburban' to create a consistent and comprehensive gridded population data product at 1 km x 1 km spatial resolution. The mapping product is based on British National Grid (OSGB36 datum). Full details about this dataset can be found at https://doi.org/10.5285/7beefde9-c520-4ddf-897a-0167e8918595

Age_GroupsAge - 4 CategoriesThis table provides Census 2021 estimates that classify People by Age - 4 Categories at Census 2021 Data Zone level. The table contains 15,120 counts.National Statistics ThemeCensus 2021CoverageCensus 2021 Data ZoneContact nameCensus Customer ServicesContact number028 9025 5156Contact emailcensus@nisra.gov.ukNational Statistics DataYesResponsible StatisticianDr David MarshallYear of data2021VariablesAge - 4 CategoriesDescription of dataThis table provides Census 2021 estimates that classify People by Age - 4 Categories at Census 2021 Data Zone level. The table contains 15,120 counts.AbstractThe census collected information on the usually resident population of Northern Ireland on Census Day (21 March 2021).Initial contact letters or questionnaire packs were delivered to every household and communal establishment, and residents were asked to complete online or return the questionnaire with information as correct on Census Day.Special arrangements were made to enumerate special groups such as students, members of the Travellers Community, HM Forces personnel etc.The Census Coverage Survey (an independent doorstep survey) followed between 12 May and 29 June 2021 and was used to adjust the census counts for under-enumeration.Disclosure control methodsStatistical disclosure control (SDC) refers to a range of methods that aim to protect individuals, households, businesses, and their attributes from being identified in published information.NISRA has taken steps to ensure that the confidentiality of respondents is fully protected.All published results from the census have been subject to statistical processes to ensure that individuals cannot be identified. These processes may result in very marginal differences between tables for the same statistic.For Census 2021, NISRA is applying two strategies - targeted record swapping (TRS) and cell key perturbation (CKP), to ensure individuals are protected from identification while minimising the impact on the quality of results.Disclosure control methodologyFor more information, please refer to:Statistical disclosure control methodologyMethodologyThe census questionnaire including the questions asked and the administrative procedures involved in collecting the census data underwent substantial testing. Coding of the data was subject to quality checks.The quality of the results was improved by the use of edit and imputation procedures for missing or incorrect data, and the data were adjusted for over and under-enumeration.The outputs reflect the complete usually-resident population of Northern Ireland.Methodology overviewFurther information on the methodology used in Census 2021 is available in the:Census 2021 methodology overviewQuality issuesThe census results underwent an extensive quality assurance process, which included checks against administrative data sources and information on particular groups such as students and HM Forces personnel.Edit procedures were applied to obviously incorrect responses (such as someone aged 180) and were designed to correct the mistake by making the least possible change to the data.Imputation procedures were applied to missing data on a returned questionnaire, and drew on responses to the question from people with similar characteristics.Quality assurance reportFurther information on the quality assurance processes used in Census 2021 is available in the:Census 2021 quality assurance reportStatement about data qualityFor more information on data quality, including response rate and item response rate, please refer to the:Census 2021 statement about data qualityGeographic referencingIrish National GridNational Statistics publicationCensus statistics are produced by the Northern Ireland Statistics and Research Agency free from political influence and have been assessed as National Statistics by the Office for Statistics Regulation.Office for Statistics RegulationMore information is available on the following web site:Office for Statistics RegulationProducing census statisticsCensus 2021 statistics meet the highest standards of trust, quality and value and are produced using standards set out in the statutory Code of Practice for Statistics.Code of Practice for StatisticsMore information is available in the:Code of Practice for StatisticsDate of publicationJune 2023Further informationCensus 2021 results webpage

This file contains the National Statistics Postcode Lookup (NSPL) for the United Kingdom as at August 2022 in Comma Separated Variable (CSV) and ASCII text (TXT) formats. To download the zip file click the Download button. The NSPL relates both current and terminated postcodes to a range of current statutory geographies via ‘best-fit’ allocation from the 2021 Census Output Areas (national parks and Workplace Zones are exempt from ‘best-fit’ and use ‘exact-fit’ allocations) for England and Wales. Scotland and Northern Ireland has the 2011 Census Output AreasIt supports the production of area based statistics from postcoded data. The NSPL is produced by ONS Geography, who provide geographic support to the Office for National Statistics (ONS) and geographic services used by other organisations. The NSPL is issued quarterly. (File size - 184 MB).

The population of the United Kingdom in 2024 was estimated to be approximately 69.3 million, with over 9.6 million people living in South East England. London had the next highest population, at almost 9.1 million people, followed by the North West England at 7.7 million. With the UK's population generally concentrated in England, most English regions have larger populations than the constituent countries of Scotland, Wales, and Northern Ireland, which had populations of 5.5 million, 3.2 million, and 1.9 million respectively. English counties and cities The United Kingdom is a patchwork of various regional units, within England the largest of these are the regions shown here, which show how London, along with the rest of South East England had around 18 million people living there in this year. The next significant regional units in England are the 47 metropolitan and ceremonial counties. After London, the metropolitan counties of the West Midlands, Greater Manchester, and West Yorkshire were the biggest of these counties, due to covering the large urban areas of Birmingham, Manchester, and Leeds respectively. Regional divisions in Scotland, Wales and Northern Ireland The smaller countries that comprise the United Kingdom each have different local subdivisions. Within Scotland these are called council areas, whereas in Wales the main regional units are called unitary authorities. Scotland's largest Council Area by population is that of Glasgow City at over 650,000, while in Wales, it was the Cardiff Unitary Authority at around 384,000. Northern Ireland, on the other hand, has eleven local government districts, the largest of which is Belfast with a population of approxiamtely 352,000.