| Açuã River | |
| Pushpin Map: | Brazil |
| River System: | Mucuim River |
| Mouth Coordinates: | -7.1987°N -64.192°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Açuã River (Portuguese: Rio Açuã) is a river of Amazonas state in north-western Brazil, a tributary of the Mucuim River.
The river flows through the Mapinguari National Park, a conservation unit created in 2008.To the north of the national park it is crossed by the Trans-Amazonian Highway (BR-230), then runs through the Balata-Tufari National Forest, where it joins the Mucuim.