The Pran Buri River (in Thai pronounced as /mɛ̂ːnáːm prāːn būrīː/) is a river in Prachuap Khiri Khan Province, Thailand, on the Kra Isthmus of the Malay Peninsula. The Pran Buri River originates in southern part of the Kaeng Krachan National Park in the Tenasserim Hills and after 130km (80miles) empties into the Gulf of Thailand. The only town along the river course is Pran Buri, the center of the Pran Buri District. The watershed of the Pran Buri River has an area of about 2000km2.
The Pran Buri dam was built in 1978, to protect lowlands from flooding as well as to have steady water flow for irrigation. The 42m (138feet) high and 1500m (4,900feet) wide earthen dam creates an artificial lake, which covers 35.2km2 and has a capacity of 445e6m3.
At the river's estuary at the Gulf of Thailand is Pran Buri Forest Park, covering 3.17km2 of mixed forest and mangrove forest. It was created in 1982.