The number of people in Ireland who say they have 'no religion' increased by 74%, according to data from last year's Census.
The latest figures also show there are also fewer Catholics in the country.
The CSO breakdown shows that the number of Catholics dropped by almost 130,000 since 2011.
However, there are still 3,729,115 Catholics in the country - accounting for 78.3% of the population.
County Offaly has the highest number of people who say they're Catholic at 88.8%, while Dun Laoghaire-Rathdown has the fewest with 69.9%.
The number of Muslim people in Ireland increased by 28.9% to over 63,000.
Almost 470,000 people, meanwhile, said they had no religion - compared to 204,151 in 2011.
The CSO has also detailed statistics related to ethnicity, explaining: "'White Irish' remains by far the largest group, accounting for 3,854,226 (82.2%) usual residents. This was followed by 'Any other White background' (9.5%), non-Chinese Asian (1.7%) and 'other incl. mixed background' (1.5%)."
Image: CSO
The latest detailed Census report also highlights statistics related to Irish Travellers.
According to the statistics gathered last April, there were 30,987 usually resident Irish Travellers recorded - of which 60% were aged under 25.
Almost 8 in 10 (78.6%) Travellers lived in cities or towns (of 1,500 or more) - compared with 62.4% of the total population.
Dublin city and its suburbs had the largest number of Irish Travellers with 5,089 people, followed by Galway and Cork.
