The Ireland General Register Office (Oifig An Ard-Chláraitheora) is the central civil repositoryA repository is a place (physical or online) where collections of original source data are stored and maintained. for records relating to Births, Marriages, and Deaths in Ireland.
In 2020 each Certificate costs €20, or €4 per Uncertified photocopy.
Link: Ireland GRO Certificate Ordering