| Coco River | |
| Pushpin Map: | Brazil |
| Source1 Location: | Tocantins state |
| Mouth Coordinates: | -9.2352°N -49.9668°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Mouth: | Araguaia River |
The Coco River (pt|Rio do Coco) is a river of Tocantins state in central Brazil. It is a tributary of the Araguaia River and forms part of the Tocantins basin.
The lower portion of the Coco River forms the eastern boundary of the Cantão State Park, and the western boundary of the Ilha do Bananal/Cantão Environmental Protection Area.This section was probably originally a meander of the Javaés River, in turn a branch of the Araguaia. The frequently flooded Cantão region between the Coco and Araguaia rivers holds an ecotone between the Amazon and Cerrado biomes.