The town was built in 1921 as a resort by the colonial French settlers to offer an escape from the heat, humidity of Phnom Penh. Nine hundred lives were lost in nine months during the construction of the resort in this remote mountain location.

The centrepiece of the resort was the grand Bokor Palace Hotel & Casino, complemented by shops, a post office, a church and the Royal Apartments. It is also an important cultural site, showing how the colonial settlers spent their free time.

Bokor Hill was abandoned first by the French in late 1940s, during the First Indochina War, because of local insurrections guided by the Khmer Issarak, and then for good in 1972, as Khmer Rouge took over the area. During the Vietnamese invasion in 1979, Khmer Rouge entrenched themselves and held on tightly for months. In earlier 1990s Bokor Hill was still one of the last strongholds of Khmer Rouge.