Beccari's free-tailed bat or Beccari's mastiff bat (Mormopterus beccarii) is a species of bat in the family Molossidae, the free-tailed bats. It is native to Australia, Indonesia, and Papua New Guinea. This bat can be found in several habitat types, including savanna, tropical moist forest, and fragmented and urban habitat. It roosts in trees, caves, and buildings in small colonies. This is a common species which is not considered to be threatened.