| Río grande de Matagalpa | |
| Pushpin Map: | Nicaragua |
| Pushpin Map Caption: | Location of mouth |
| Mouth Location: | South Caribbean Autonomous Region |
| Mouth Coordinates: | 12.9°N -115°W |
| Subdivision Type1: | Country |
| Length: | 267miles |
Río Grande de Matagalpa (pronounced as /es/, Awaltara in Miskito, Ucumulalí in Matagalpa) is a river of Nicaragua. Running 430km (270miles) from its source near Matagalpa to the Caribbean Sea in the northern part of the South Caribbean Autonomous Region it is the second longest river in Nicaragua. It gives it name to the city and municipality of La Cruz de Río Grande. The Tumarín Dam is being constructed on its lower reaches.