Established in 1927, it has an area of 2,750.52 square kilometres (1,061.98 sq mi) with a total population of 157,887 people as of 2017.

A large part of its territory corresponds to the historical-geographical region of Sabina.

It is bordered to the west, along the river Tiber by the province of Viterbo and to the south-west by the Metropolitan City of Rome Capital.

Lago del Salto is the largest in the Lazio region and is situated at an altitude of 1,755 metres (5,758 ft).

[4] There are numerous natural oases, castles, fortresses and Franciscan sanctuaries dotted about the province of Rieti.