| Sewa | |
| Map: | SierraLeoneOMC.png |
| Subdivision Type1: | Country |
| Subdivision Name1: | Sierra Leone |
| Subdivision Type3: | Province |
| Subdivision Name3: | Eastern, Southern |
| Subdivision Type4: | District |
| Subdivision Name4: | Kono District, Kenema District, Bo District, Bonthe District |
| Length: | 240km (150miles) |
| Discharge1 Location: | Near mouth |
| Discharge1 Avg: | (Period: 1971–2000) [1] |
| Source1 Location: | Confluence of the Bagbe River and Bafi River |
| Source1 Coordinates: | 8.6997°N -11.2545°W |
| Source1 Elevation: | 323m (1,060feet) |
| Mouth Location: | Sherbro River (Atlantic Ocean) |
| Mouth Coordinates: | 7.3093°N -12.1379°W |
| Mouth Elevation: | 0m (00feet) |
| River System: | Sewa River |
| Basin Size: | 19022km2[2] |
| Tributaries Left: | Makon |
| Tributaries Right: | Falima River, Tigpoye, Bebeye, Tibo, Tabe |
Sewa River is a river in Sierra Leone.[3] Its furthest sources are the Bagbe River and Bafi River, which originates in the mountainous areas of the northeastern part of the country, near the border with Guinea. From the confluence of Bagbe and Bafi in the Kono District Sewa flows in a south-southwestern direction and drains an area of . Close to the Atlantic coast the river joins Waanje River to form the Kittam River. Kittam River flows 48km (30miles) westwards along the coast and enters a network of lagoons and streams separated from the sea by Turner's Peninsula. By the island of Sherbro, Kittam empties into the larger estuary Sherbro River.
Sewa River is navigable over shorter distances, but in the middle and upper reaches, rapids and cataracts dominate.
The river has great commercial value for Sierra Leone. Sewa's upper reaches is being panned for diamonds on a large scale. Closer to the coast rice cultivation and the cultivation of piassava, exported for the production of besoms, are important crops.