| Cuinarana River | |
| Pushpin Map: | Brazil |
| River System: | Marapanim River |
| Mouth Coordinates: | -0.6973°N -47.6096°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Cuinarana River (Portuguese: Rio Cuinarana) is a river in the state of Pará, Brazil, a tributary of the Marapanim River.
The river originates near the village of Magalhães Barata, and flows north to the point where it enters the Marapanim River.The mangroves of the east side of the Cuinarana River are protected by the Maracanã Marine Extractive Reserve.On the west side the mangroves are protected by the Cuinarana Marine Extractive Reserve.The west bank of the Marapanim River, and the peninsula to the left of the mouth of the estuary formed by the Marapanim and Cuinarana rivers is protected by the Mestre Lucindo Marine Extractive Reserve.
The mouth of the river is mainly mud flats.The area around Rio Cuinarana has a low population, with about 18 people per square kilometre.The area has a monsoon climate. The average temperature is . The hottest month is September at and the coldest month is January at . Rainfall averages annually. The wettest month is March with and the driest is October with .