The Buzău river in eastern Romania is a tributary of the river Siret. Its total length is 302 km, and its drainage basin area is 5,264 km2. Its source is in the south-eastern Carpathian Mountains, east of Brașov. The Buzău flows through the Romanian counties Brașov, Covasna, Buzău and Brăila. It flows into the Siret in Voinești, close to its confluence with the Danube, west of Galați.