Karuah River, an open semi-mature tide dominated drowned valley estuary[4] is located in the Mid North Coast and Hunter regions of New South Wales, Australia.

Karuah River rises on the southeastern slopes of Gloucester Tops of the Great Dividing Range, below The Mountaineer, southwest of Gloucester, and flows generally southeast and south.

joined by eleven tributaries including the Telegherry, Mammy Johnsons, and The Branch rivers, before reaching its mouth within Port Stephens at Karuah, and then flows out to the Tasman Sea of the South Pacific Ocean.

The river descends 600 metres (2,000 ft) over its 101 kilometres (63 mi) course.

[3] Initially named Clyde by Lachlan Macquarie, the use of the Aboriginal name became prevalent subsequently.