The Ombrone (Latin: Umbro) is a 160-kilometre (99 mi) long river in Tuscany, central Italy.

Ombrone
Confluence of the Arbia (left) and Ombrone (right) south of Buonconvento.
Location
Country	Italy
Physical characteristics
Source
• location	San Gusmè
• elevation	about 420 m (1,380 ft)
Mouth
• location	Tyrrhenian Sea
Length	160 km (99 mi)
Basin size	3,494 km2 (1,349 sq mi)
Discharge
• average	32 m3/s (1,100 cu ft/s) at the mouth

The Ombrone's source is at San Gusmè, near Castelnuovo Berardenga, on the south-eastern side of the Monti del Chianti. After a twisting route, it receives the waters of the tributaries Arbia, Merse and Orcia before reaching the plain near Istia d'Ombrone.^[1]

It subsequently passes near the city of Grosseto, before flowing into the Tyrrhenian Sea.