| Buy River | |
| Map: | Kama basin.png |
| Map Size: | 200 |
| Source1 Location: | Kuyedinsky District |
| Mouth: | Kama |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Length: | 228km (142miles) |
| Mouth Coordinates: | 56.2064°N 54.1911°W |
| Basin Size: | 6530km2 |
Buy (Russian: Буй; Bashkir: Беүә, Bewä) is a river in Perm Krai, the Republic of Bashkortostan and the Republic of Udmurtia, Russia. It is a left tributary of the Kama.[1] It is 228km (142miles)long, with a drainage basin of 6530km2.[2]
It starts in the south of Perm Krai, in the Kuyedinsky District. Then, it flows through northwestern Bashkortostan and into the Kama River within the Udmurt Republic, to the south of the town of Kambarka.
Main tributaries: