| São Mateus River | |
| Pushpin Map: | Brazil |
| Source1 Location: | São Félix de Minas - Minas Gerais |
| Mouth Location: | South Atlantic Ocean |
| Mouth Coordinates: | -18.6042°N -39.7275°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Brazil |
| Length: | 224km (139miles) (north fork), 188km (117miles) (south fork)[1] |
| Basin Size: | 103350NaN0 |
The São Mateus River is a river primarily in Espírito Santo state in eastern Brazil.[2]
The São Mateus River rises in the Brazilian state of Minas Gerais in the municipality of São Félix de Minas, where it is known as Braço Sul do Rio São Mateus (the southern branch) or Rio Cricaré. Its principal tributary is the Cotoxé River (or northern branch), which also arises in Minas Gerais near the source of the southern branch, in an area called "Alto São Mateus".[3] The two come together near the village of Lagoa at, and the São Mateus River flows 65 more kilometers, through the city of São Mateus, and empties into the South Atlantic Ocean near the town of Conceição da Barra, in the state of Espírito Santo. In addition, other rivers such as the São Domingos, the Santana, the Mariricu, and the Rio Prêto are part of the São Mateus River's hydrological system.