Vulcan is a city in Hunedoara County, in the Transylvania region of Romania. It lies in the Jiu Valley, a coal-mining area of the Southern Carpathians, and with a population of 19,772 as of 2021 it is the second-largest city in that valley.
The city administers two villages, Dealul Babii and Jiu-Paroșeni, the latter also known by its Hungarian name, Zsilymacesdparoseny. Its position in the Jiu Valley places it within one of Romania's principal coal-producing districts, alongside the neighbouring settlements of the region.