The Jiu is a river in southern Romania. It is formed near Petroșani by the confluence of headwaters Jiul de Vest and Jiul de Est.
It flows southward through the Romanian counties Hunedoara, Gorj, Mehedinți and Dolj before flowing into the Danube near Zăval, a few kilometers upstream from the Bulgarian city of Oryahovo. It is 339 kilometres long, including its source river, Jiul de Vest. It has a basin of 10,430 km2. Its average discharge at the mouth is 97 m3/s.
