Macauã River is a river of Acre state in western Brazil, a tributary of the Iaco River.

The river forms most of the southeast boundary of the 176,349 hectares (435,770 acres) Macauã National Forest, a sustainable use conservation unit created in 1988. It flows through the northern part of the 21,148 hectares (52,260 acres) São Francisco National Forest, a sustainable use conservation unit created in 2001. It then flows through the eastern part of the 750,795 hectares (1,855,250 acres) Cazumbá-Iracema Extractive Reserve, established in 2002 to support sustainable use of the natural resources by the traditional population.

• List of rivers of Acre