The 2,079 Church of Ireland members in the county made up 1.6% of its total population.
Pope Francis shows his approval in St Peter's Square.
Catholicism remains the predominant religion, accounting for 87% (113,481) of Mayo's population in April 2016.
The 3,729,115 Catholics recorded in Census 2016 was 132,220 fewer than in 2011.
Offaly was revealed to be the county with the highest percentage of Catholics per capita, with 88.6% reporting Catholic. It's an increase of 73.6 percent in five years, making it the fastest growing "religion".
Ireland's Orthodox Christians grew by 37.5% between now and the last census, and that group is made up mostly of Romanians. There are 63,443 members of Ireland's Muslim community which is nearly double the number recorded in 2006.
Other changes in the religious make-up of the country included a 28.9% increase in the number of Muslim residents.
The numbers of Travellers in Kilkenny rose by 12.8% in Kilkenny between the years 2011 and 2016, according to new data from the most recent Census. In 2011, the 1,087 people with no religion comprised 2.8% of the county's population.
Perhaps unsurprisingly, the average age of marriage is much lower in Traveller families, with those families likely going on to have much more children than the average household. By 2016, this had increased to 9,747 people comprising 7.6% of the county's population.
Details on ethnicity and the Travelling community were also released.
Census 2016 also showed that Travellers were more urbanised than the general population with nearly 8 in 10 (78.6%) living in cities or towns (of 1,500 or more), compared with 62.4% of the total population.Dublin city and suburbs had the largest number of Irish Travellers with 5,089 persons.This was followed by Galway city and suburbs with 1,598 persons and Cork city and suburbs with 1,222. Over half (52.6%) of all Travellers in the county were aged under 20, compared to just under 3 in 10 (29.7%) of the county's overall population.
There are 730 Irish Travellers living in Longford town, the second highest number among towns of a population of 1,500 or more persons.
It found that there were 761 Irish Travellers enumerated in the county in April 2016. Dublin city and suburbs had the largest number of Irish Travellers with 5,089 persons.