| Ribeira Principal | |
| Source1 Location: | Serra Malagueta Santiago Island, Cape Verde |
| Source1 Elevation: | 900m (3,000feet) |
| Subdivision Type1: | Country |
| Subdivision Name1: | Cape Verde |
| Length: | 8km (05miles) |
| Mouth Location: | Atlantic Ocean near Achada Monte |
| Mouth Coordinates: | 15.247°N -23.656°W |
Ribeira Principal is a stream in the northern part of the island of Santiago, Cape Verde. It flows completely within the municipality of São Miguel. Its source is in the Serra Malagueta mountains. It flows generally north, through the valley of Principal, and joins the Atlantic Ocean near Achada Monte.