Census of Ireland

The census of Ireland is typically held on a quinquennial basis by the Central Statistics Office to determine the population of the Republic of Ireland. The most recent census was held in 2022. As of November 2022, the next census was planned to occur in 2027.

Dates of census

 * Sunday, 18 April 1926
 * Sunday, 26 April 1936
 * Sunday, 12 May 1946
 * Sunday, 8 April 1951
 * Sunday, 8 April 1956
 * Sunday, 9 April 1961
 * Sunday, 17 April 1966
 * Sunday, 18 April 1971
 * Sunday, 1 April 1979
 * Sunday, 5 April 1981
 * Sunday, 13 April 1986
 * Sunday, 21 April 1991
 * Sunday, 28 April 1996
 * Sunday, 28 April 2002
 * Sunday, 23 April 2006
 * Sunday, 10 April 2011
 * Sunday, 24 April 2016
 * Sunday, 3 April 2022

Political geography
Under Article 16 of the Constitution of Ireland, revisions of Dáil constituencies by the Oireachtas are required at a minimum every 12 years. However, they must also have due regard to changes in the population. Under the Electoral Reform Act 2022, the Electoral Commission is required to conduct a review of constituency boundaries after every census. From 1997 up to the establishment of the Electoral Commission in 2023, this function was carried out by a Constituency Commission created for this function.

Urban geography
From 1971 to 2006, census towns were "defined as a cluster of 50 or more occupied dwellings where, within a radius of 800 metres, there was a nucleus of 30 occupied dwellings". From 2016, a new census settlement was defined "as a minimum of 50 occupied dwellings, with a maximum distance between any dwelling and the building closest to it of 100 metres, accompanied by evidence of an urban centre". For the 2022 census, the CSO developed a new urban geography term the Built Up Area (BUA) to define urban areas.