Milleretta is an extinct genus of millerettid stem-group reptile from the Late Permian of what is now South Africa. Fossils have been found in the Balfour Formation. Its only known species is Milleretta rubidgei, although several other species of millerettid have been synonymized with this genus. Milleretta and its close relatives are unique among Paleozoic stem reptiles in that it secondarily closed an upper and lower temporal fenestra during ontogeny.