| Moei River | |
| Name Other: | Thaungyin River |
| Subdivision Type1: | Country |
| Subdivision Name1: | Thailand, Burma |
| Subdivision Type2: | State |
| Subdivision Name2: | Tak Province, Mae Hong Son Province |
| Subdivision Type4: | District |
| Subdivision Name4: | Phop Phra, Mae Sot, Mae Ramat, Tha Song Yang, Sop Moei |
| Subdivision Type5: | City |
| Subdivision Name5: | Mae Sot |
| Length: | 327km (203miles) |
| Source1 Location: | Thanon Thongchai Range, Tak Province, Thailand |
| Source1 Coordinates: | 16.4847°N 98.8569°W |
| Mouth: | Salween River |
| Mouth Location: | Sop Moei, Mae Hong Son Province, Thailand |
| Mouth Coordinates: | 17.7858°N 97.7425°W |
| Mouth Elevation: | 76m (249feet) |
| Tributaries Right: | Yuam River |
The Moei River (in Thai pronounced as /mɛ̂ːnáːm mɤːj/), also known as the Thaungyin River (Burmese: သောင်ရင်းမြစ်;) is a tributary of the Salween River. Unlike most rivers in Thailand, the Moei River flows north in a northwest direction. It originates in Phop Phra District, Tak Province, flowing then from south to north across Mae Sot, Mae Ramat, and Tha Song Yang Districts, finally entering the Salween River within the limits of Sop Moei District of Mae Hong Son Province. The river is 327km (203miles) long.
The Yuam River joins its left bank only 7km (04miles) before its confluence with the Salween. Many fish species inhabit its waters, including the giant river catfish.[1]
The Moei River forms a portion of the border between Thailand and Myanmar.
The river is the scene of clashes between the Tatmadaw and Karen militias.[2] Often Karen people cross the river either in order to enter Thailand as refugees or to go back to Burma.[3]
Flow of refugees increased as fighting in Burma intensified in 2024.[4] [5] [6]