|Main source||Gremyachy Klyuch, Zelenodolsky District, Tatarstan|
|River mouth||Kuybyshev Reservoir, Volga, near Vasilyevo, Zelenodolsky District, Tatarstan
53 m (174 ft)
|Basin size||250 km2 (97 sq mi)|
|Length||37 km (23 mi)|
The Sumka (Russian: Сумка) is a river in Zelenodolsky District of the Republic of Tatarstan, Russia, a left-bank tributary of the Volga River. It is 37 kilometres (23 mi) long, and its drainage basin covers 250 square kilometres (97 sq mi). It begins near Gremyachy Klyuch and flows to the Kuybyshev Reservoir, Volga, forming the western border of Vasilyevo, Tatarstan.
The river valley comes through the Raifa section of the Volga-Kama Reserve. There the Sumka passes several major lakes, the biggest being Raifa lake. The maximal mineralization 200 mg/l. The maximal water discharge is 30 cubic metres per second (1,100 cu ft/s). The river used to dry up in summer.