| Maracanã River | |
| Pushpin Map: | Brazil |
| Source1 Location: | Castanhal, Pará |
| Source1 Coordinates: | -1.4774°N -47.6925°W |
| Mouth Coordinates: | -0.701°N -47.4876°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Tributaries Left: | Caripi River |
The Maracanã River (Portuguese: Rio Maracanã) is a river of the state of Pará, Brazil.
The Maracanã is a meandering river with a main channel that varies in depth in its lower reaches from 15to.It rises in the south of the municipality of Castanhal, Pará, then flows in a northeast direction to the Atlantic Ocean at Maracanã, Pará.The river is lowest between September and October and highest between February and April.Its main tributary is the Caripi River, which enters the Maracanã from the left.
Santarém Novo is on the right bank of the river about from its mouth on the Atlantic.The Chocoaré - Mato Grosso Extractive Reserve protects part of the right (east) shore of the Maracanã River.The lower reaches of the Maracanã River, before it empties into the Atlantic Ocean beside Maiandeua Island, are protected by the Maracanã Marine Extractive Reserve, created in 2002.The municipality and town of Maracanã are at the mouth of the river.
The vegetation around the Maracanã River is mostly savanna.The area around the river has a relatively small population, with 38 people per square kilometre. Temperatures average . The hottest month is July, with, and the coldest month is April, with . Annual rainfall averages . The wettest month is March, with and the driest is October, with .