The Nambung River is a river in the Wheatbelt region of Western Australia, north of Perth. The river drains an area between the towns of Cervantes and Badgingarra. In its lower reaches the Nambung River forms a chain of waterholes in the Nambung Wetlands where it disappears underground into a limestone karst system from the Indian Ocean.
The Nambung River was encountered by explorer George Grey on 16 April 1839, during his second disastrous expedition along the Western Australian coast. He named it the Smith River after Frederick Smith, a member of his party who died from exhaustion during the final days of the expedition. Smith was the 18-year-old grandson of William Smith, prominent M.P. for Norwich, and was a first cousin to Florence Nightingale.
It was renamed the Nambung River by government surveyor John Sherlock Brooking in 1874-75. The Nambung River's longest tributary was subsequently named Frederick Smith Creek.
The river was recorde