Lazio is a region with ordinary statute in central Italy, with Rome as its capital. With 5 702 947 inhabitants it is the second most populated region in Italy after Lombardy, and the ninth largest in terms of surface area. It borders Tuscany to the north-west, Umbria to the north, Marche and Abruzzo to the north-east and Molise and Campania to the south-east.

To the west, however, it is washed by the Tyrrhenian Sea, and within it lies the small enclave of Vatican City. In remote antiquity, Latium (Latium) comprised only a limited part of the present region, between the lower reaches of the Tiber, the Tyrrhenian Sea, the Pontine Marshes and the Sabine Mountains.