Irish births, marriages and deaths
Civil Registration of births, marriages and deaths began on 1 January 1864, although non-catholic marriages were recorded from 1845.
Registers for all of Ireland up to 1921, and for the Republic of Ireland, from 1922 to the present day, are held at the General Register of Ireland: you can find information on these certificates at https://www.irishgenealogy.ie/en/
Registers for Northern Ireland, including those prior to 1922, are held at the General Register Office for Northern Ireland (GRONI): you can find information on these certificates at http://www.nidirect.gov.uk/gro