| Vajiralongkorn Dam | |
| Name Official: | Vajiralongkorn Dam |
| Location Map: | Thailand |
| Coordinates: | 14.7994°N 98.5969°W |
| Dam Crosses: | Khwae Noi River |
| Country: | Thailand |
| Location: | Thong Pha Phum, Kanchanaburi |
| Operator: | Electricity Generating Authority of Thailand |
| Construction Began: | 1979 |
| Opening: | 1984 |
| Dam Type: | Embankment, concrete-face rock-fill |
| Dam Height: | 920NaN0 |
| Dam Length: | 10190NaN0 |
| Dam Width Base: | 100NaN0 |
| Dam Volume: | 8,860 million m3 |
| Res Surface: | 388 km2 |
| Plant Turbines: | 3 × 100 MW Francis-type |
| Plant Capacity: | 300 MW |
| Plant Annual Gen: | 760 GWh |
Vajiralongkorn Dam (Thai: เขื่อนวชิราลงกรณ;), also called the Khao Laem Dam (Thai: เขื่อนเขาแหลม),[1] is a concrete-faced rock-fill dam (CFRD)[2] in Thong Pha Phum District in Kanchanaburi, Thailand. The dam lies across the Khwae Noi River (River Kwai) and was renamed Vajiralongkorn Dam after King Vajiralongkorn on 13 July 2001 when he was crown prince. Vajiralongkorn Dam is Thailand's first CFRD and supplies a 300 MW hydroelectric power station with water. The dam was built and is managed by the Electricity Generating Authority of Thailand (EGAT).
Dam construction began in 1979 and took five years to complete. Its reservoir started filling with water in June, 1984. Three 100MW hydropower generators came on line in October and December 1984 and February 1985 respectively. The reservoir created by the dam has a maximum storage capacity of 8,860 million m3 inundating 388 square km2.[3] Average runoff into the reservoir is approximately 5,500 million m3 per year.