For the first time in Northern Ireland's history, Catholics outnumber Protestants the latest Census figures show.
The 2021 Census reveals 45.7% of the population are Catholic with 43.5% recording themselves as Protestant.
Meanwhile, 1.5% identified themselves as being from other non-Christian backgrounds.
In a separate figure, the Census recorded the background of people with 48% coming from a Protestant background and 45% Catholic.
Around 42.8% of people identified themselves as British the Census found, with 33.3% identifying themselves as Irish. In 2011, that figure was 48.4% for British and 28.4%.
Meanwhile, 31.5% have identified themselves as Northern Irish. That was 29.4% in 2011.
The usual resident population has been recorded as 1,903,175 - the highest ever in Northern Ireland.
The census also revealed an increase in the number of people holding Irish passports in Northern Ireland.
Some may seek to draw a direct link between the religious breakdown and public opinion on the potential reunification of Ireland.
However, critics of that approach view religious affiliation as a crude metric to measure sentiment on the constitutional question, insisting that just because someone is Protestant or Catholic does not necessarily mean their respective political outlooks are unionist or nationalist.
Under the terms of the 1998 Good Friday Agreement peace deal, the constitutional status of Northern Ireland can be changed only with the consent of its population.
The incumbent Northern Ireland Secretary is obliged to call a referendum on Irish unity if he or she believes there has been a shift in public opinion that would indicate a majority in favour of constitutional change.
However, the 1998 peace accord provided no detail on what metrics or criteria should be relied upon to make this judgment call.
The figures on religion and national identity are part of the second round of data being published from Census 2021.
The first tranche of figures, published in May, related to population and household numbers.
It showed that Northern Ireland's population had risen to a record high of more than 1.9million.
Further census details will be released over the coming months with details on labour market statistics and qualifications expected in the winter.
The main census topics will be revealed in Spring/Summer 2023 with a further geographical breakdown of all statistics being provided in Summer 2023.
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