The Tristan Moorhen (Gallinula nesiotis) is an extinct flightless rail from the South Atlantic island of Tristan da Cunha.
The once common Tristan Moorhen had become rare by 1873 and was extinct by the end of 19th century because of hunting, predation by introduced species (rats, cats, pigs, etc.) and habitat destruction by fire.
A handful of taxidermical specimens of the Tristan Moorhen have been preserved, including one at Harvard University.
The Tristan Moorhen looked similar to the closely related Gough Moorhen, G. comeri, of Gough Island, located 395 miles to the southeast.
In 1956, the Gough Moorhen was introduced to Tristan da Cunha. In 1984, its population on the island of Tristan was estimated to consist of about 250 pairs; however, it is now increasingly accepted that this is actually a recovering population of the Tristan Moorhan, rather than being members of the closely related Gough Moorhen family.