| Cassiporé River | |
| Pushpin Map: | Brazil |
| Pushpin Map Caption: | Mouth location in Brazil |
| Source1 Location: | Amapá state |
| Mouth Coordinates: | 3.901°N -51.1561°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Cassiporé River is a river of Amapá state in north-eastern Brazil.
Cabo Cassiporé is a low promontory about east of the wide entrance to the river.The land from Cabo Orange to the north and Cabo Cassiporé is low and often flooded, with shallow water up to from the shore.
The Cassiporé river can be navigated by boats drawing under as far as the village of Japa, 24 miles inland.The tidal range at the river mouth is less than .The Cassiporé River runs through the most northern part of the Amapá mangroves ecoregion along the bay where it flows into the Atlantic Ocean.