| Ajajú River | |
| Map Size: | 300 |
| Pushpin Map Size: | 300 |
| Subdivision Type1: | Country |
| Subdivision Name1: | Colombia |
| Length: | 770km (480miles)[1] |
| Mouth: | Apaporis River |
| Mouth Location: | confluence with Tunía River, Caquetá, Colombia |
| Mouth Coordinates: | 1.1847°N -72.7269°W |
Ajajú River is a river of Colombia and a tributary of Apaporis River. It is part of the Amazon River basin.