Religion in Northern Ireland: What does the Census tell us?

The 2021 Census tells us that people in Northern Ireland are much more likely to identify as Christians, of one type or another, than people in most other parts of Europe. Nearly 80 percent of the population identified as Christians in the Census: 42 percent as Catholic and 37 percent as Protestant or other Christian denominations. But the Census also confirmed a significant rise in those who indicated that they have ‘no religion’, from 10 percent in 2011 to 17 percent in 2021.

We do not yet have the data from the 2021 Census in England and Wales, but it is instructive to use figures from their 2011 Census as a point of comparison. Then, 59 percent identified as Christian, 25 percent as no religion, and 5 percent as Muslim. You may be surprised that as many as 59 percent chose Christianity on the England and Wales Census in 2011. A number of studies since then have found that the ‘no religion’ group is now the largest ‘religious’ group in England and Wales.

Here, it is worth mentioning that Censuses, in many countries, can produce figures that over-estimate religious affiliation. This is because Censuses often ask the question about religion differently than other surveys. For example, the question on the 2011 Census in England and Wales was ‘what is your religion?’, which may prompt respondents to assume that they have a religion, even if they almost never think about or practice religion in their everyday lives.

Let me illustrate how this works. In 2011, Humanists UK commissioned a poll ahead of the Census that asked the religion question in two ways. When asked ‘what is your religion?’, 61 percent chose Christian and other, while 39 percent chose ‘no religion’. But when asked ‘are you religious?’, 29 percent said yes and 65 percent said no.

Historically, ‘what is your religion?’ is the wording that has been used on the religion question on the Census in the Republic of Ireland, although it was changed for the 2022 Census to read, ‘What is your religion, if any?’, with the first option listed as ‘no religion’.  We do not yet have the results of the Republic’s Census, but I would expect that the change in question wording will contribute to a significant rise from the 10 percent who chose no religion in the 2016 Census.

Since 2001, religion questions on the Northern Ireland Census have been more nuanced. People are asked ‘Do you regard yourself as belonging to any particular religion?’ Those who answer no are directed to a ‘community background’ question, which asks, ‘What religion, religious denomination or body were you brought up in?’ In the 2021 Census, when the results of the religion and religious background questions are combined, 45.7 percent of the population is Catholic/from a Catholic background, while 43.5 percent is Protestant/from a Protestant background.

You may have noticed a discrepancy in the religious identification figures and religious background figures among Catholics and Protestants – it appears Catholic identification is ‘stickier’ than Protestant affiliation:


2021 Northern Ireland Census: Religious Identification & Religious Background

Religious Identity Religious Identity + Background
Catholic 42% 46%
Protestant 37% 43%


This is a common trend internationally: historically Catholic countries tend to maintain higher levels of religious identification than historically Protestant ones. We might extrapolate from this that among those who chose ‘no religion’, more are from Protestant than Catholic backgrounds. Northern Ireland’s Statistics and Research Agency (NISRA) has not yet released all the multi-variable tables for the 2021 Census, so I cannot tell you this with certainty, but it seems reasonable and would be in line with the 2011 trends. This assertion is further supported by the ‘no religion’ data by geographic region, which has been released. Geographically, areas in which people of Protestant backgrounds are a majority have higher levels of ‘no religion’ – as high as 31 percent in Ards and North Down – making this region (religiously at least!) more like England than Fermanagh or Tyrone:


2021 Northern Ireland Census: Religious Identification by Area

Region Percent ‘No Religion’
Northern Ireland 17%
Antrim & Newtownabbey 23%
Armagh City, Banbridge & Craigavon 15%
Belfast 22%
Causeway Coast & Glens 15%
Derry City & Strabane 8%
Fermanagh & Omagh 8%
Lisburn & Castlereagh 24%
Mid & East Antrim 22%
Mid Ulster 8%
Newry, Mourne & Down 11%
Ards & North Down 31%


We also can be fairly certain that people in the younger age groups are more likely to choose ‘no religion’. This is a strong trend in the Republic, where in the 2016 Census about 15 percent of those aged 15-34 identified as no religion, compared to 10 percent of the general population. Other surveys put the no religion figure much higher among young people; for example in the 2016 European Social Survey, 39 percent of 16-29-year-olds in the Republic chose ‘no religion’, compared to 54 percent who chose Catholic.

Returning to Northern Ireland, the jump from 10 to 17 percent of people of ‘no religion’ between 2011 and 2021 may initially seem surprising. But when data from the yearly Northern Ireland Life & Times survey is taken into account, it is not.  By 2019, 20 percent of people were choosing ‘no religion’ in the Life & Times survey. Those figures jumped dramatically to 27 percent in 2020 and 28 percent in 2021, though I suspect these figures are artificially inflated due to changes in the way the data was gathered (entirely online in 2020 and 98 percent online in 2021).

All of this is to say that I think that taking into account the way the Census question was asked (which is less likely to artificially inflate religiosity than in some other Censuses), we can safely say around 17 to 20 percent of people in Northern Ireland have ‘no religion’; and they are more likely to be from Protestant backgrounds. We can also fairly safely say that this trend is strongest among young people.

But in Northern Ireland it is likely that there are other factors at play, working to keep religious identification artificially high. Even if our Census question is more nuanced, it is unlikely to be able to fully overcome our divided history, where for some people religious identification may be a political act rather than a faith-based response. Internationally, it is also common for relatively high levels of religious vitality to persist in contexts where religion contributes to so-called ‘cultural defense’ against oppositional ‘others’ (for example, see work by sociologists of religion David Martin or Steve Bruce). Even though it has been more than two decades since the peace agreement, ethno-national divisions between ‘Catholics’ and ‘Protestants’ remain significant, and often oppositional. Brexit, and the conversations it has sparked about the possibility of a united Ireland, may have strengthened (or at least not weakened) the phenomenon of religious identification as a political act.

Similarly, during the Troubles it was often argued that Northern Ireland’s unusually high levels of religious attendance also were linked to ‘cultural defense’ – going to church was a way to associate with the community or the tribe. There also is evidence that societies with higher levels of ‘existential insecurity’ are more religious (for example, see work by political scientists Pippa Norris and Ronald Inglehart) – and surely the Troubles were a time of ‘existential insecurity’.

So perhaps it is not surprising that since the peace agreement, attendance has declined, dramatically among Catholics and somewhat more steadily among Protestants. Despite declines, these religious attendance figures are among the highest in Europe – although young people are less likely than their parents and grandparents to take up a pew. Moreover, in-person church attendance was disrupted during the COVID-19 pandemic and it remains to be seen how this will impact on religious identification and attendance in the long-term.


Monthly or more attendance at religious services over time (NIL&TS)

1999 2008 2012 2019
Catholic 77% 68% 54% 46%
Protestant 52% 52% 45% 46%


At the same time, despite Northern Ireland’s continued polarization there is also evidence that traditional forms of political identification in Northern Ireland are weakening: the 2019 Life & Times Survey revealed that 50 percent of people now choose ‘neither’ nationalist or unionist rather than choose nationalist or unionist political identities. These ‘neithers’ are disproportionately young (59 percent of 18-24-year-olds).

The dynamics of religious and political change are more complicated and complex than can be captured in Census and survey data. But it is safe to say there are links between the weakening of traditional political identities and the decline in religious identifications and the rise of ‘no religion’: how it all unravels remains to be seen.

(Image: Maghera Old Church, at the rear of Maghera Church of Ireland Parish Church, Corrigs Road (near Maghera), County Down, Northern Ireland, May 2011, by Ardfern, Wikimedia Commons)


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