The Archdiocese of Dublin is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church located in the eastern part of Ireland. Its archepiscopal see includes the republic's capital city – Dublin. The cathedral church of the archdiocese is St Mary's Pro-Cathedral. Dublin was formally recognised as a metropolitan province in 1152 by the Synod of Kells. Its second archbishop, Lorcán Ua Tuathail, is also its patron saint.

St Mary's Church, known also as St Mary's Pro-Cathedral or simply the Pro-Cathedral, the Chapel in Marlborough Street or the Pro, is a pro-cathedral and is the episcopal seat of the Roman Catholic Archbishop of Dublin and Primate of Ireland.