The population of Northern Ireland is 1,903,100.
This data comes from the 2021 census and is an increase of 92,312 or 5.1% since the previous 2011 census.
Northern Ireland is a part of the United Kingdom, located in the North East of the island of Ireland and makes up around 3% of the UK population.
It was created in 1921 when the Ireland was partitioned. The unionist and largely Protestant population of the six provinces wanted to remain within the United Kingdom rather than join the newly independent Republic of Ireland.
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Northern Ireland Population Growth
In common with the rest of Ireland, the population of the six counties that now make up Northern Ireland fell dramatically during the second half of the 19th century.
The depopulation of Ireland was triggered by the Great Famine (also known as the Potato Famine) of 1845-49. Mass starvation led to emigration to North America and elsewhere in the British Empire, which continued for the next 50 years.
Over those five decades, the population of Northern Ireland fell from 1.6 million to 1.2 million, a fall of 25%.
Since 1891, the population of Northern Ireland has increased between every census. In the 2001 census its population passed the pre-famine peak of 1841, and the population has continued to grow to 1.9 million in 2021.
By 2031 there is a good chance that the number of people living in Northern Ireland will pass 2 million.
Largest cities in Northern Ireland
Belfast is the capital city and the largest city in Northern Ireland, and the second largest city on the island of Ireland. It is also the 11th largest city in the United Kingdom.
Other major cities and towns in Northern Ireland are Derry, Craigavon, Newtownabbey, Bangor and Lisburn.
The table below lists the population of the ten largest towns and cities in Northern Ireland in 2020.
Northern Ireland Religious Demographics
Although Northern Ireland is ethnically fairly homogenous, it is starkly divided among religious lines between Protestants and Catholics.
This division has had a massive impact on the people and politics of Northern Ireland, and has often been a major factor in violent conflict – most recently the 30 year Troubles.
At the time of partition, around two thirds of the population in Northern Ireland’s six counties were Protestant – largely descended from British colonists. This was a major reason why Northern Ireland did not join with the other Irish counties to form the Republic of Ireland.
Since then, the religious demographics of Northern Ireland have gradually changed. The 2021 census recorded that, for the first time in centuries, there were more people of Catholic background (45.7%) in Northern Ireland than there were of Protestant or other Christian background (43.5%).
Somewhat overshadowed by the Christian divide within Northern Ireland, in the 2021 census 1.3% of people stated that they had another religion than Christianity. And 17.4% of people stated that they had no religion.
Northern Ireland Ethnic Demographics
For all its religious divisions, Northern Ireland is the most ethnically homogenous part of the United Kingdom.
In the 2021 census 96.8% of people in Northern Ireland confirmed that they considered themselves to be white. This is a significant fall from 20 years earlier – in 2001, 99.25% of people living in NI reported that they were white.
The other main ethnic groups in Northern Ireland in 2021 are Asian / Asian British, Black or Black British or Mixed.
The table below lists the ethnicity of people in Northern Ireland:
Northern Ireland Language
In common with the other nations of the United Kingdom, English is the most widely spoken language. In 2021, 95.4% of people in NI speak English as their first language.
The next most commonly spoken first language is Polish, spoken by 1.1% of people, then Lithuanian which is spoken by 0.5% of people.
Irish comes fourth in the list – 0.32% of people (that’s 5,969 people) reported that it was their first language, an increase from 0.24% in 2011.
Irish and Ulster Scots are both protected languages, recognised in the European Charter for Regional or Minority Languages.
Northern Ireland Population Density
The total area of Northern Ireland is 14,130 km2(5,460 sq miles). This means that, based on the 2021 census, the population density of NI is 135 people per km2 or 349.6 people per square mile.