Manicoré River is a river of Amazonas state in north-western Brazil. It is a tributary of the Madeira River and merges into this river about 3 km upstream from the town of Manicoré. The headwaters of the river are in the Campos Amazônicos National Park, a 961318 ha protected area created in 2006 that holds an unusual enclave of cerrado vegetation in the Amazon rainforest. Further north the river defines part of the eastern boundary of the 151993 ha Campos de Manicoré Environmental Protection Area, created in April 2016 just before the provisional removal of president Dilma Rousseff. It then flows through the 359138 ha Manicoré Biological Reserve, which was created at the same time.