Terni is a city located in the southern portion of the Umbria region in central Italy. It sits near the border with the Lazio region and serves as the capital of the province of Terni. The city is situated in the plain of the River Nera.
Geographically, Terni is positioned 104 kilometres northeast of Rome and 81 kilometres south of Perugia, the regional capital. It has a population of 106,272, making it the 42nd-largest city in Italy.