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 Synod of Kells took place in 1152, under the presidency of Giovanni Cardinal Paparoni, and continued the process begun at the Synod of Ráth Breasail (1111) of reforming the Irish church. The sessions were divided between the abbeys of Kells and Mellifont, and in later times the synod has been called the Synod of Kells-Mellifont and the Synod of Mellifont-Kells.