Sangu River, locally a conch river, is a hilly river located in the Chittagong Hill Tracts region in the south of Bangladesh. It is the second largest river in Chittagong division after Kornafuli. The Sangu River is one of the few rivers that originate in the interior of Bangladesh. It flows through Bandarban district and South Chittagong and merges into the Bay of Bengal. The length of this river from its source to the Bay of Bengal is 180 km.

Sangu river is the main river of Bandban district. Bandarban district town is also located on the banks of this river. The river Sangu is closely associated with the livelihood of this district. This river is one of the means of communication in the hilly areas of Bandarban.
The Sangu River is one of the few hilly rivers in Bangladesh. Bandarban district and the southern part of Chittagong. Most of the rivers of Bangladesh flow from north to south and merge into the Bay of Bengal. But the Sangu River formed in the southern part of Bandarban, flowed north and ended in the Bay of Bengal.