| Avacha | |
| Pushpin Map: | Russia |
| Pushpin Map Caption: | Location of mouth |
| Mouth: | Pacific Ocean |
| Mouth Location: | Avacha Bay |
| Mouth Coordinates: | 53.0285°N 158.5056°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Length: | 122km (76miles) |
| Basin Size: | 5090km2 |
Avacha is a river in the southern part of the Kamchatka Peninsula, Russia. It flows southeast into Avacha Bay, near Petropavlovsk-Kamchatsky. The river is 122km (76miles) long with a watershed of 5090km2. Nineteenth-century travelers like George Kennan ascended the Avacha as far as possible and then took horses to the upper course of the river Kamchatka to travel further north.
The town of Yelizovo, which houses the Petropavlovsk-Kamchatsky Airport, is on the banks of the Avacha.