The Archdiocese of Cashel and Emly is a Latin diocese of the Catholic Church located in mid-western Ireland, and the metropolis of the eponymous ecclesiastical province. The cathedral church of the archdiocese is the Cathedral of the Assumption in Thurles, County Tipperary. The incumbent archbishop, as of 2024, is Kieran O'Reilly.

The Cathedral of the Assumption is the mother church of the Metropolitan Province of Cashel and the cathedral church of the Roman Catholic Archdiocese of Cashel and Emly in Thurles, County Tipperary in Ireland. It is the cathedra of the Archbishop of Cashel and Emly and stands on the site of earlier chapels, which were the only Roman Catholic churches in Thurles. Following the English Reformation, many archdiocesan assets, including the cathedral at the Rock of Cashel were appropriated by the established church. James Butler II (1774–91), on being appointed by the Holy See, moved his residence and cathedra from Cashel, favouring Thurles instead, where his successors continue to reign today.