Mount Tukosmera is the tallest mountain on Tanna, Vanuatu. It is located in the southern part of the island. It was a volcano in the Pleistocene, but is no longer active, unlike Mount Yasur. The mountain has special religious significance for the adherents of the John Frum movement, as a place from which gods come.

A 6,000-hectare (15,000-acre) tract of the upper slopes of the mountain has been recognised as an Important Bird Area (IBA) by BirdLife International because it contains a breeding site for a population of collared petrels.