Demographics of NI: What religions are followed by the people living here?

FactCheckNI has been researching and publishing a short series of articles exploring the demographics of Northern Ireland, examining changes in population age, religion and place of birth.

These articles are designed to be a reference point for anyone interested in what has changed – and what has stayed the same – across the past few decades and more. 

The first piece considered where the people who live here were born, the second looked at how our population is ageing. This final article examines religion and explores trends in what religious beliefs, if any, the people who live here hold

Highlight facts include:

• Comparisons between the 1926 Census and the latest equivalent data show that the proportion of the population identifying as Catholic has risen from 33% to 42% (around 800,000).
• The 2021 Census  found the Catholic proportion of the population to be higher than it was in the 1861 Census – the first time this has happened in 160 years.
• In contrast, the proportion describing themselves as Protestant has shrunk from 66% to 37% – currently around 700,000 people.
• Over the same period, those either not stating a religion or saying they have none has had a marked increase; from 0.2% to 19%, and altogether this now accounts for over 350,000 people.
• Other religions have become more of a feature of local life, still just accounting for 1.3% of the population today, having been 0.1% a century ago.
• Among the others, the most common single religion is Islam. The 2021 Census recorded a total of 10,870 Muslims in NI (0.57% of the population), up from 1,983 in 2001.
• In the same two decades, the number of Hindus increased from 825 to 4,190 (0.22% of the population), the number of Buddhists grew from 533 to 1,542 (0.08%), and the number of Jews grew from 365 to 439 (0.02%).
• There are a couple of dozen further “Other” religions with relatively tiny followings, including 116 Satanists, 37 Druids and 16 Scientologists.
• Of course, there is no guarantee that people respond to the Census truthfully. In 2011, 57 said their religion was Heavy Metal.

Northern Ireland is changing in many ways.

Perhaps one of the clearest is in the religious make up of the population. The traditional divide into Protestants and Catholics is now inadequate, largely because of the growth of people who have no religion (or choose not to say what that is). That third bloc now represents almost 20% of all people.

The most commonly-stated religion is now Catholic, representing 43% of the population – a proportion that is now higher than it was 100 years ago.

In contrast, the proportion of people who say they are Protestant has reduced substantially in the time since 1926, and now sits at 37%.

Then there are the “Others”. This group, representing any and all other religions, has also grown in the past century, albeit that growth is nowhere near as dramatic as the group who say they have no religion (or don’t say what that is).

Now to get into the details of the changing religious demographics of Northern Ireland.

It’s important to be aware how the approach to tracking different religions has changed over time:  firstly, with a change to questions in the Census and, secondly, about some of our own reconfigurations to ensure that comparing historical data with the situation today makes a bit more sense.

• Changing Census

This article focuses on census data, which provides a comprehensive assessment of the religious composition of the population every ten years.

Historically, people living here have been asked every decade what religion they followed and these answers were compiled into census data. However, the past three censuses have been different, with two main questions on religion.

One takes an historical approach. Respondents were asked to state their “current religion”. The other asks them about “religion brought up in”, which is an effort to detail people’s community background, even if they do not identify with a specific church or consider themselves actually religious.

We mention this now because appreciating this difference is essential for understanding what some of the statistics below say (or do not say). For the purposes of exploring the changing religious demographics over time, we will measure the historical approach (used in every census up to 1991) and the more recent “current religion” (used in censuses since 2001).

• Moving with the times

Few readers are likely to be surprised by the biggest trend in NI religion over the past century. What was once two blocs – Protestants and Catholics – has shifted in recent decades to a shape with three main pillars: Protestant, Catholic and None.

However, what they might find more interesting is in how these first two, now three blocs measure against each other.

We will look later at the thousands of people in NI who follow other religions; this presents another challenge when comparing today’s Northern Ireland with that of the past.

Historically, the religious “Others” category was composed almost entirely of small Protestant denominations (Brethren, Baptists, Free Presbyterians, Salvation Army, etc.), whereas in recent censuses it also includes growing communities (Muslims, Hindus, Sikhs, Buddhists, Orthodox Christians, and others). Treating this category consistently across time would therefore either understate Protestants in the past or overstate them today.

However, FactCheckNI has combed through the fine details of various census data to iron out these kinks. We have re-coded each denomination individually, effectively widening the umbrella of what is meant by ‘Protestant’ by folding in the smaller Protestant communities with the larger ones usually associated with that religion in censuses (Church of Ireland, Presbyterian and Methodist).

That allows us to track, with more consistency, the major changes in NI religion over time.

• Big picture

Based on our fresh analysis of Census data, we can graph the main trends in the religious composition of Northern Ireland’s population since 1926.

Figure 1 – source: Census data

Major changes between 1926 and the latest figures include that:

• The percentage of the population describing themselves as Protestant has fallen from 66% to 37%. At the 2021 Census, this comprised roughly 700,000 people.
• The Catholic proportion of the population has grown from 33% to 42% (around 800,000 people).
• Those either not stating a religion or professing no belief has grown from 0.2% of the population to 19% (over 350,000).
• Other religious beliefs have increased from 0.1% to 1.3%.

Note that the Catholic share in 1981 looks unusually low, based on overall trends, but this may not represent any real demographic shift. The 1981 Census involved a partial boycott from the Catholic/Nationalist community which will have distorted results. The effect appears to have been a slump in responses saying Catholic and an inflation in responses of “Not stated”.

• Catholic boomerang

Going back further, the percentage of the population in Northern Ireland (and the six counties that would become Northern Ireland after partition) considering themselves Catholic has followed a U-shaped pattern.

This proportion fell in the decades following the 1860s before slowly rising from the 1930s onwards; 2021 was the first subsequent census where the Catholic proportion of the population was higher than that recorded in 1861.

Figure 2 – source: Census data

• Religion brought up in

What about the other question: what religion were people brought up in?

Focusing on the main two religious groups in NI, Catholic and Protestant (using the broader categorisation discussed above, including a wider number of Protestant and other non-Catholic Christian faiths, rather than just Presbyterians, Methodists and the Church of Ireland), it is possible to see the difference between the numbers of people who say they grew up in particular religious backgrounds set against the number of people who say they follow those religions now.

The following two tables compare the total number of people who said they were brought up in a particular religious background with the number who currently identify with that religion, at the time of the censuses in 2001, 2011 and 2021.

Figure 3 – source: Census data

Figure 4 – source: Census data

There are only three censuses worth of data on this and, because of that, it is difficult to glean any major patterns from the results.

Nonetheless, all these details are key aspects of the changing religious demographics of Northern Ireland over time.

• A closer look at Others

What about the “Others”? They make up only 1.3% of our population, but underneath that single statistic lies a number of small communities in and across Northern Ireland.

The Others have also grown, up from just 0.1% of the population since 1921 (this growth is not nearly as dramatic as the rise in No religion/Not stated, which went from 0.2% to 19% in the same century, but it is a notable increase, nonetheless).

Currently, the bulk of the Others comprises Islam, Hinduism and “Orthodox (combined)”, which refers to all Orthodox Christian groups combined together (including Romanian Orthodox, Russian Orthodox, Greek Orthodox and other Eastern Orthodox churches).

For a significant time, Judaism was the largest “Other” religion in NI but this is no longer the case.

Between 1926 – when there were 1,352 Jews in NI – and 1971, Judaism was the largest of these four groups within Northern Ireland. Today, however, it amounts to a smaller proportion of the population than those other three groups, with 439 people recorded in the 2021 Census (a slight increase on the 365 recorded in 2001). This means that, according to the latest census data, around 0.02% of the NI population subscribes to Judaism.

Figure 3 – source: Census data

In the past couple of decades, Islam, Hinduism and the Orthodox religions have all seen significant growth in Northern Ireland.

The 2021 Census recorded 10,870 Muslims in NI (0.57%) and 4,190 Hindus (0.22%) – up from 1,983 and 825 respectively in 2001.

• The other Others

Buddhism is the largest single Other religion outside Judaism, Islam, Hinduism and the combined Orthodox churches, with 1,542 practitioners, or 0.08% of the population, according to the 2021 Census – up from 533 in 2001.

In 2021 there were 29 separate religions listed on the census findings under “Other religions”, including 16 self-described followers of Scientology, 37 Druids and 116 Satanists.

There were also 781 people who described themselves as Jedi Knights – although this is officially recorded as a subcategory of “No religion”.

Most responses stating “No religion” are not part of any subcategory – around 330,000 people – but other delineations include agnostic (567 people), atheist (475) and humanist (241).

It is of course impossible to say whether people answered the census truthfully; it is possible that the 59 people who responded to the 2011 Census by saying their religion was “Heavy Metal” were not being completely serious.