Tags: Clerical Administrative Region, Diocese.
The Diocese of Tortona (Latin: Dioecesis Derthonensis) is a Roman Catholic ecclesiastical territory in northern Italy spanning parts of three regions of Piedmont (Province of Alessandria) Lombardy (Province of Pavia) and Liguria (Province of Genoa). It is a suffragan of the Archdiocese of Genoa and forms part of the ecclesiastical region of Liguria.
