| Namwan River 南宛河 | |
| River System: | Irrawaddy River |
| Source1 Location: | Huguo Township, Longchuan County, Dehong |
| Source1 Elevation: | 2,520 m |
| Mouth Location: | Nongdao Town, Ruili City, Dehong |
| Mouth Coordinates: | 23.8442°N 97.6444°W |
| Mouth Elevation: | 743 m |
| Basin Size: | 1,439 km² |
| Basin Population: | 132,000 (2004)[1] |
| Length: | 148.5 km |
| Discharge1 Avg: | 11.3 m³/s (Maliba hydrological station at Chengzi, Longchuan)[2] |
Namwan River (Chinese: 南宛河; ᥘᥛᥳ ᥝᥢᥰ) is a river in China and Myanmar. Namwan River rises in the mountain called Ganya Liangzi at the northern section of Longchuan County, Yunnan. It through the Longchuan county, as the major irrigation water source of the fields in the basin. And entering the valley at the southwest of Zhangfeng, the county town of Longchuan. Then it became the boundary between Myanmar and China until it entering Shweli River at Nongdao, Ruili.[1]