| Caçanje River | |
| Pushpin Map: | Brazil |
| River System: | Cuiabá River |
| Source1 Location: | Mato Grosso state |
| Mouth Location: | Cuiabá River |
| Mouth Coordinates: | -16.6987°N -56.4878°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Tributaries Right: | Alegre River |
The Caçanje River (Portuguese: Rio Caçanje), also called the Cassange River, is a river of Mato Grosso state in western Brazil. It is a tributary of the Cuiabá River.
The Caçanje River defines part of the northern border of the Encontro das Águas State Park, then flows northeast to join the Cuiabá River.Further south the Alegre River flows northeast across the park parallel to the Caçanje, forms part of the eastern border, then continues east to join the Caçanje just before that river enters the Cuiabá.The region, rich in watercourses, supports diverse pantanal vegetation.