| Urugua-í River | |
| Pushpin Map: | Brazil |
| River System: | Paraná River |
| Source1 Location: | Bernardo de Irigoyen, Misiones |
| Mouth Coordinates: | -25.8988°N -54.6132°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
The Urugua-í River (Spanish; Castilian: Arroyo Urugua-í) is a river in the Misiones Province of Argentina. It is a tributary of the Paraná River.
The Urugua-í River, also called the Marambas or Grande River, has a length of about, including the reservoir formed by the Urugua-í Dam.Tributaries include the Sarita River, Arroyo de las Cabeceras and Uruzú River.The Urugua-í River flows through the southern part of the Urugua-í Provincial Park in a southeast – northwest direction and is impounded by the Urugua-í Dam to the west of the park.The park was created in part to compensate for the flooding of of the lower Urugua-í River basin caused by construction of the dam.