Roman Catholic Diocese of Celaya Tags: Clerical Administrative Region, Diocese.The Roman Catholic Diocese of Celaya (Latin: Dioecesis Celayensis) (erected 13 October 1973) is a suffragan diocese of the Archdiocese of León. It was a suffragan of the Archdiocese of San Luis Potosí until 25 November 2006. thumbnail area (km2) 8.7697e+09 Established 13 October 1973 ( years ago) province Roman Catholic Archdiocese of León Learn more... Loading...