Lake Oku is a crater lake on the Bamenda Plateau in the Northwest Region of Cameroon. It is located at 2,227 metres (7,306 ft) on Mount Oku, and is completely surrounded by cloud forest. Lake Oku has no specific protection but is surrounded by montane forest, with a thin belt protected as a government “Plant life Sanctuary”. The rest of the forest is under community-based management and there are no settlements around the lake.

The lake is the only known habitat of the Lake Oku Clawed Frog. The Lake Oku clawed frog (Xenopus longipes) is a species of frog in the family Pipidae. It is a small, dark-coloured, fully aquatic frog with males growing to an average of 28–31 mm and females 32–36 mm. The name results from the claws at the ends of its two hind feet. Its back is brown and the belly is speckled black on an orange background. The frog is fully aquatic, never observed to come out of the water. The International Union for Conservation of Nature has rated this frog as “critically endangered” on the basis of its small area of occurrence at a single location, and the possibility that introduction of non-native fish into the lake could cause the frog to be wiped out.