Roman Catholic Diocese of Senigallia Tags: Clerical Administrative Region, Diocese.The Diocese of Senigallia (Latin: Dioecesis Senogalliensis) is a Roman Catholic ecclesiastical territory in the Marche Italy. It has existed since the sixth century. It is a suffragan of the archdiocese of Ancona-Osimo. thumbnail area (km2) 5.8e+08 country Italy Established 6th Century province Roman Catholic Archdiocese of Ancona-Osimo Learn more... Loading...