| Madeirinha River | |
| Pushpin Map: | Brazil |
| River System: | Roosevelt River |
| Source1 Location: | Mato Grosso state |
| Mouth Location: | Roosevelt River, Amazonas state |
| Mouth Coordinates: | -8.5187°N -60.958°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
Madeirinha River is a river of Mato Grosso and Amazonas states in north-western Brazil, a left tributary of the Roosevelt River.
In Mato Grosso the river forms the western boundary of the Rio Madeirinha Ecological Station, a fully protected environmental unit created in 1997.It then flows north east through the Tucumã State Park in Mato Grosso and the Manicoré State Forest in Amazonas, a sustainable use conservation unit created in 2005.It continues north east from the state forest before joining the Roosevelt river.