Italian Provinces ordered by region

Provinces are regulated in Title V, Part II of the Constitution and in primary and secondary sources. All provinces, except the autonomous Trento and Bolzano which enjoy special autonomy, and the Valle d'Aosta where the provincial functions are carried out by the Region, are part of the UPI, the Union of Provinces of Italy, an association to which metropolitan cities also belong. Provinces include a number of comuni, which in their turn can be subdivided into frazioni. Within a general restructuring of the Italian administration, provinces, as well as smaller communes, may be in the next few years suppressed and incorporated.

In the Roman empires the term Provinciae was used for territories outside the Italian peninsula, which was instead divided into Regiones; as a matter of fact, the term derived form the participle pro-victa (=defeated before, conquered). The Roman province was the largest administrative unit of the foreign possessions, and after the administrative reform begun by Diocletian became a third degree subdivision of the Roman Empire (Praefecturae, Dioceses and Provinciae).

Italy (excluding the major islands) was considered ager romanus (=territory of Rome) and under Augustus was divided into eleven Regiones: Latium et Campania; Apulia et Calabria; Lucania et Bruttium; Samnium; Etruria; Picenum; Umbria; Aemilia; Venetia et Histria; Liguria; Transpadana). The term regio -onis derived from the verb regĕre (=to govern), which came to signify the administered territory.

Although Provinces are only administrative entities, they have existed for centuries and many geographical divisions and services are still located in the Province capitals. Provinces existed even before the unification of Italy in many of the former states, but their territories did not correspond to present day entities. The administrative subdivision of the kingdom of Sardinia was extended to the rest of Italy, as more territories were being annexed. This organization was based on the French model of Province, Circondari, Mandamenti and Comuni. In the early 2000s, following a trend of savings on the local administrations, provinces were deprived of most of their functions, and in 2014 ten provinces became città metropolitane.

At the proclamation of the Kingdom of Italy in 1861, the provinceswere only 59, and today's Veneto, the eastern part of Mantua, Friuli-Venezia Giulia and Trentino-Alto Adige were still part of the Hapsburg Empire, while Lazio had remained in the Papal State. Many provinces of the Kingdom of the Two Sicilies passed directly from the pre-unification governments to the new state, only the province of Benevento was newly created.

Under the Fascist government (1923-1943) many territorial changes were made and in 1927 the largest province of Terra di Lavoro was suppressed, and many new provinces were created: Aosta, Bolzano, Brindisi, Castrogiovanni (later Enna), Frosinone, Gorizia, Matera, Nuoro, Pescara, Pistoia, Ragusa, Rieti, Savona, Terni, Varese, Vercelli and Viterbo.

After the Second World War, a number of new provinces were also established, or their territories redefined: Bolzano and Trento (1948), Trieste (1954), Pordenone (1968), Isernia (1970), Oristano (1974). In 1992 eight new provinces were created: Biella, Crotone, Lecco, Lodi, Prato, Rimini, Verbano-Cusio-Ossola and Vibo Valentia, and in 2004the three provinces of Monza e Brianza, Fermo and Barletta-Andria-Trani. After a short division in 2003 into eight provinces, in 2016 the Sardegna region was reorganized into five provinces.

After 2016, Provinces are due to be dismantled as administrative units, as established by Law no.56 of April 7, 2014, and converted into second level administrative bodies elected by limited suffrage, while other provinces have already become metropolitan cities: Bari, Bologna, Firenze, Genova, Milano, Napoli, Roma, Torino, Venezia, Reggio Calabria. However, Provinces will remain as geographical and historical entities.