The Wang Thong River (Thai: แคววังทอง, rtgs: Khwae Wang Thong, IPA: [kʰwɛː waŋ tʰɔːŋ], also known as the Khek River) is a river in Thailand. Its source lies in the Phetchabun Mountains in the Khao Kho District, Thailand. It flows through Thung Salaeng Luang National Park and forms Namtok Sri Dit and Namtok Kaeng Sopha (Kaeng Sopha Waterfall) in the Wang Thong District of Phitsanulok Province, and finally flows through into the Bang Krathum District, passing through Ban Sam Ruen and on to the border of Phitsanulok and Phichit, where it drains into the Nan River at (16°31′06″N100°19′36″E).