Stung Treng was first a part of the Khmer Empire, then the Lao kingdom of Lan Xang and later the Lao kingdom of Champassack. After the Franco-Siamese war of 1893, Chiang Taeng (Stung Treng) was administated by French Lower Laos from 1893-1904. In 1904 the province was traded by French Laos for the exchange for Champassak in French Protectorate of Cambodia which left a small manorities of Laotians in Cambodia.
Owing to its border location and forested mountain areas in the northeast of the province, there was much communist guerrilla activity in Stung Treng during Cambodia's recent past. The insurgency lasted from the Vietnamese infiltration in the 1950s until the late Khmer Rouge years.