| Alatyr | |
| Pushpin Map: | Russia |
| Pushpin Map Caption: | Location of mouth |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Length: | 296km (184miles) |
| Source1 Coordinates: | 54.792°N 45.114°W |
| Mouth: | Sura |
| Basin Size: | 11200km2 |
| Tributaries Right: | Insar |
The Alatyr (Russian: Алатырь|p=ɐˈɫatɨrʲ) is a river in Mordovia, Russia, and it is the left tributary of the river Sura.[1] It is long, and has a drainage basin of .[2] The Alatyr freezes up in November and stays icebound until April. The towns of Ardatov and Alatyr (myv|Ратор, Erzya: Rator), are located on the Alatyr River.[3]