The following is alist of the Catholic dioceses in Italy. As of May 2017[update], theCatholic Church in Italy is divided into sixteenecclesiastical regions. While they are similar to the 20civil regions of the Italian state, there are some differences. Most ecclesiastical regions are in turn divided into a number ofecclesiastical provinces. The provinces are in turn divided into a number ofdioceses. The sovereign state ofVatican City is part of the metropolitan province ofRome. Ametropolitan bishop exercises a degree of leadership over a group of dioceses that are loosely subject (suffragan) to the care of the metropolitansee. This list excludes those archdioceses, dioceses and ecclesiastical territories that areimmediately subject to theHoly See.
There are 227 sees ('particular churches'), most of which aredioceses led by abishop. A diocese that is led by anarchbishop is known as anarchdiocese. There are 40 Metropolitan archdioceses which serve as the seat of anecclesiastical province. This number includes theHoly See and thePatriarchate of Venice. There are also four archdioceses which are non-metropolitan, having been demoted by papal decree. This brings the number of archbishops in Italy andVatican City to 44 (i.e. 40 + 4).
All the sees belong to theLatin Church apart from threeEastern Catholic sees of theItalo-Albanian Catholic Church that use theByzantine Rite in theAlbanian language. All sees of the Latin Church use theRoman Rite apart from theMetropolitan Archdiocese of Milan, which mainly uses theAmbrosian Rite.

| Map Code | Ecclesiastical Region | Ecclesiastical Province |
|---|---|---|
| 1 | Abruzzo-Molise | |
| L'Aquila inAbruzzo | ||
| Chieti-Vasto in Abruzzo | ||
| Pescara-Penne in Abruzzo | ||
| Campobasso-Boiano inMolise | ||
| 2 | Basilicata | |
| Potenza-Muro Lucano-Marsico Nuovo | ||
| 3 | Calabria | |
| Calabria-Bova | ||
| Catanzaro-Squillace | ||
| Cosenza-Bisignano | ||
| 4 | Campania | |
| Salerno-Campagna-Acerno | ||
| Benevento | ||
| Naples | ||
| 5 | Emilia-Romagna | |
| Bologna | ||
| Modena-Nonantola | ||
| Ravenna-Cervia | ||
| 6 | Lazio | |
| Rome | ||
| 7 | Liguria | |
| Genoa | ||
| 8 | Lombardy | |
| Milan | ||
| 9 | Marche | |
| Ancona-Osimo | ||
| Fermo | ||
| Pesaro | ||
| 10 | Piedmont | |
| TurinincludingAosta Valley | ||
| VercelliinPiedmont | ||
| 11 | Puglia | |
| Bari-Bitonto | ||
| Foggia-Bovino | ||
| Lecce | ||
| Taranto | ||
| 12 | Sardinia | |
| Cagliari | ||
| Oristano | ||
| Sassari | ||
| 13 | Sicily | |
| Agrigento | ||
| Catania | ||
| Messina-Lipari | ||
| Palermo | ||
| Syracuse | ||
| 14 | Tuscany | |
| Florence | ||
| Pisa | ||
| Siena-Colle di Val d'Elsa-Montalcino | ||
| 15 | Triveneto | |
| GoriziainFriuli-Venezia Giulia | ||
| UdineinFriuli-Venezia Giulia | ||
| TrentoinTrentino-Alto Adige/Südtirol | ||
| VeniceinVeneto | ||
| 16 | Umbria | |
| Perugia-Città della Pieve |
The following are immediately Subject to the Holy See, despite not being in the Pope's Ecclesiastical Province of Rome.
(Byzantine Rite, the only non-Latin dioceses in Italy)
The ecclesiastical provinces of L'Aquila, Chieti-Vasto and Pescara-Penne are mainly situated in thecivil region ofAbruzzo while Campobasso-Boiano is situated inMolise.

In the ecclesiastical region ofTriveneto, there are two ecclesiastical provinces that are situated in the civil region ofFriuli-Venezia Giulia (Gorizia and Udine); one province that is mainly situated in the civil region ofTrentino-Alto Adige/Südtirol (Trento); and one province that is mainly situated in the civil region ofVeneto (Venice).