The Mongkol Borey River (Central Khmer: ស្ទឹងមង្គលបុរី [Mang Kul Buo Rei],) is a river in Mongkol Borey District in Banteay Meanchey Province in northwestern Cambodia. It flows from the border of Chanthaburi Province of Thailand and runs through Mongkol Borey and neighboring districts.[1] It is a major tributary of the Tonlé Sap.[2]
The Khmer Rouge destroyed a bridge which once crossed the river.