Ruak River
Confluence of Ruak River with Mekong River, view from Wat Phra That Doi Pu Khao [th] in Ban Sop Ruak
Native name	แม่น้ำรวก (Thai)
Location
Country	Myanmar and Thailand
Physical characteristics
Source
• location	Daen Lao Range, Shan Hills
Mouth
• location	Mekong at Ban Sop Ruak, Chiang Saen District
• coordinates	20°21′16″N 100°4′57″E / 20.35444°N 100.08250°E / 20.35444; 100.08250
• elevation	366 m (1,201 ft)
Basin features
Tributaries
• right	Mae Sai River

The Ruak River (Thai: แม่น้ำรวก, RTGS: Maenam Ruak, pronounced [mɛ̂ː.náːm rûa̯k]; Northern Thai: ) is a right hand tributary of the Mekong. The mouth of the Ruak river is at the Thai-Burma border opposite Laos, a spot known as the "Golden Triangle", a popular tourist destination.

Course

The Ruak originates within the hills of the Daen Lao Range, Shan State (Burma), and becomes the boundary river between Thailand and Burma at the confluence with the Mae Sai River near the northernmost point of Thailand.^[1] It then meanders eastwards until it empties into the Mekong River at Ban Sop Ruak, Tambon Wiang, Chiang Saen District, Chiang Rai Province. The boundary section of the river is 26.75 kilometres (16.62 mi) long.