| Syun | |
| Mouth Coordinates: | 55.7197°N 54.2769°W |
| Subdivision Type1: | Country |
| Length: | 209km (130miles) |
| Discharge1 Avg: | 14.8m3/s |
| Basin Size: | 4500km2 |
The Syun (Bashkir: Сөн, Sön; Russian: Сюнь; Tatar: Сөн, Sön) is a river in Bashkortostan and Tatarstan, Russian Federation, a left-bank tributary of the Belaya (Kama basin). It is 209km (130miles) long,[1] of which 74km (46miles) are in Tatarstan. Its drainage basin covers 4500km2.[1] Major tributaries in Tatarstan are the Kalmiya, Sikiya, Terpelya, Bezyada, and Sharan in Bashkortostan. The maximal water discharge is 655m3/s (1979), and the maximal mineralization 500 to 1000 mg/L. Average sediment at the mouth per year is 120mm. Drainage is regulated. Since 1978 it is protected as a "natural monument of Tatarstan".