| Ay | |
| Name Etymology: | "month" or "moon" in Bashkir language |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Subdivision Type2: | Oblasts |
| Subdivision Name2: | Chelyabinsk Oblast, Republic of Bashkortostan |
| Subdivision Type3: | Cities |
| Subdivision Name3: | Zlatoust, Kusa |
| Length Km: | 549 |
| Source1 Location: | Uraltau range |
| Mouth: | Ufa |
| Mouth Elevation: | 525 ft |
| Basin Size Km2: | 15000 |
The Ay (ba|Әй, Äy; ru|Ай) is a river in Bashkortostan and Chelyabinsk Oblast in Russia, a left tributary of the Ufa. The river is 549km (341miles) long, and its drainage basin covers 15000km2.[1] The Ay freezes up in late October or early November and remains icebound until mid-April. The cities of Zlatoust and Kusa are along the river Ay. There are many steep cliff sides and caves along the banks of the river.[2] The current of the Ay has been used for generating hydroelectric power. It is also possible to fish for pike, bleak, and carp, to name a few species.[3]