The Ombrone (Latin: Umbro) is a 160-kilometre (99 mi) long river in Tuscany, central Italy.
The Ombrone's source is near Castelnuovo Berardenga, on the south-eastern side of the Monti del Chianti. After a twisting route, it receives the waters of the tribuaries Arbia, Merse and Orcia before reaching the plain near Istia d'Ombrone.
It subsequently passes near the city of Grosseto, before flowing into the Tyrrhenian Sea.
Coordinates: 42°39′31″N 11°00′47″E / 42.65861°N 11.01306°E