| Koyon | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Subdivision Type3: | Region |
| Subdivision Name3: | Novosibirsk Oblast |
| Length: | 54km (34miles) |
| Mouth: | Berd |
| Mouth Coordinates: | 54.7598°N 83.2275°W |
| Progression: | Berd→ |
The Koyon (Russian: Коён) is a river in Iskitimsky District of Novosibirsk Oblast, Russia. It is a right tributary of the Berd. The length of the river is 54 kilometers (34 mi). By the Koyon lie the settlements of Mikhaylovka, Verkh-Koyon, Nizhny Koyon and Morozovo.