The Pasur is a river in southwestern Bangladesh and a distributary of the Ganges. It continues the Rupsa River. All the distributaries of the Pasur are tidal. It meets the Shibsa River in the Sundarbans. Near the sea, it becomes the Kunga River. The Pasur is the deepest river in Bangladesh.

It is home to Sundarbans Firefly Sanctuary, a wildlife sanctuary for regional wildlife, including the Bengal tiger.