| Ugra | |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Length: | 399km (248miles) |
| Mouth: | Oka |
| Mouth Coordinates: | 54.5072°N 36.1064°W |
| Basin Size: | 15700km2 |
The Ugra is a river in Smolensk and Kaluga Oblasts in Russia, left tributary of the Oka. The east-flowing Ugra joins the north-flowing Oka at Kaluga and the united river, called the Oka, continues east to the Volga. In the 16th century, the Ugra-Oka confluence was the western end of a line of forts protecting Muscovy from Tatar raids. The river is known for the Great stand on the Ugra River. Its length is and its basin .[1] It is frozen from late November (sometimes as late as January) until the end of March. 60% of its annual flow is snowmelt, mostly in April.
A part of the valley of the Ugra located in Kaluga Oblast belongs to Ugra National Park.[2]