Mertensophryne uzunguensis (common name: Uzungwe toad or Udzungwa toad) is a species of toad in the family Bufonidae. It is endemic to Tanzania and found on the Udzungwa Mountains and the Southern Highlands. Its natural habitats are swampy montane grasslands. It is threatened by habitat loss caused by afforestation with pines, overgrazing, and agricultural expansion. Whether its range includes the Udzungwa Mountains National Park is unknown.