Chiang Khan is a town and district in Loei Province, north-eastern Thailand. Neighbouring districts are (from the east clockwise) Pak Chom, Mueang Loei, and Tha Li of Loei Province. To the northwest are the Xaignabouli and Vientiane Provinces of Laos. The important water resources are the Mekong, Hueang and Loei Rivers.

Chiang Khan was founded in the late-19th century when Lao villagers crossed the Mekong after the French colonised Laos. More migrants later arrived from Vietnam and China. Chiang Khan became a trading hub largely due to its location on the river. People on both sides of the rivers exchanged goods, culture, and language. Trading stopped in 1975 when the communist Pathet Lao seized power from the Lao government and cut economic ties to Thailand. Chiang Khan languished until rediscovered in the early-21st century becoming a centre for tourism.