| Armu | |
| Pushpin Map: | Russia |
| Pushpin Map Caption: | Location of mouth |
| Mouth: | Bolshaya Ussurka |
| Mouth Coordinates: | 45.7631°N 135.4672°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Subdivision Type2: | Region |
| Subdivision Name2: | Primorsky Krai |
| Length: | 201km (125miles) |
| Basin Size: | 5424km2 |
The Armu (Russian: Арму) is a river in Krasnoarmeysky District of Primorsky Krai, a tributary of the Bolshaya Ussurka.
It is 201km (125miles) long. The river's drainage basin covers about 5424km2. The longest tributary of the Armu is the Obilnaya, 101km (63miles) long.
The river is a popular place of tourism and fishing. One brand of vodka has been named after it.