Cuieiras River (Demini River tributary)

Cuieiras River (Rio Cuieiras) is a river of the Barcelos municipality of Amazonas state in north-western Brazil. It is a tributary of the Demini River.

The river rises near the Serra do Aracá, the mountain after which the 1818700 ha Serra do Aracá State Park is named, and provides a route to the foot of the mountain.