Nam Ou

The Nam Ou ( Lao: ນ ້ ໍ າ ອູ, [ nâ ː m ù ː ] ) is a 448 km long river in Laos.

It rises in the province of Phongsali and ends at Pak Ou in the Mekong. There are two known caves, Tham Tham Phum Thing and at the mouth. The Nam Ou is an important thoroughfare in northern Laos, as many set on its course places are not yet connected to the road network.