|Sön, Syun River|
|Mouth||Nizhnekamsk Reservoir, Belaya River (Kama basin), Bashkortostan|
|Basin countries||Bashkortostan and Tatarstan, Russia|
|Basin area||4,500 km²|
The Syun (Bashkir: Сөн, Russian: Сюнь, Tatar Cyrillic: Сөн, Latin: Sön) is a river in Bashkortostan and Tatarstan, Russian Federation, a left-bank tributary of the Belaya River (Kama basin). Its length is 209 km (74 of them in Tatarstan) and its drainage basin is 4,500 km². Major tributaries in Tatarstan are Kalmiya, Sikiya, Terpelya, Bezyada, and Sharan in Bashkortostan. The maximal water discharge is 655 m³/s (1979), the maximal mineralization 500-1000 mg/l. Average sediment in mouth per year is 120 mm. Drainage is regulated. Since 1978 it is protected as natural monument of Tatarstan.