Megaladapis, informally known as the koala lemur, is an extinct genus of lemurs belonging to the family Megaladapidae, consisting of three species that once inhabited the island of Madagascar. The largest measured between 1.3 to 1.5 m in length.

Lemurs are wet-nosed primates of the superfamily Lemuroidea, divided into 8 families and consisting of 15 genera and around 100 existing species. They are endemic to the island of Madagascar. Most existing lemurs are small, have a pointed snout, large eyes, and a long tail. They chiefly live in trees and are active at night.