The Central Statistics Office (CSO), or in Irish, An Phríomh-Oifig Staidrimh (POS) is the statistical agency responsible for the gathering of "information relating to economic, social and general activities and conditions" in Ireland, in particular the National Census which is held every five years. The office is answerable to the Taoiseach and has its main offices in Cork. The CSO was established, on a statutory basis, by the Statistics Act, 1993 in an attempt to reduce the number of separate offices responsible for collecting statistics for the state.
The CSO had existed, as an independent ad-hoc office, within the Department of the Taoiseach since June 1949, and its work greatly increased in the coming decades particularly from 1973 with Ireland joining the European Community. Previous to the 1949 reforms, statistics were collected by the Statistics Branch of Department of Industry and Commerce on the creation of the Irish Free State in 1922. The Statistics Branch amalgamated a number of statistics gathering organisations that had existed in Ireland since 1841 when the first comprehensive census was undertaken by the Royal Irish Constabulary.
The current Director-General of the Central Statistics Office is Gerry O'Hanlon.