
Molossus is a genus of bats. The genus contains ten species with a New World distribution from Mexico in the north to northern Argentina at its most southerly limit. Four of these species have distributions that include various islands in the West Indies such as Puerto Rico or Trinidad.

Molossus alvarezi, or Alvarez's mastiff bat, is a species of bat in the family Molossidae, native to the Yucatán Peninsula. It lives within a relative homogenous environment within perennial forests, low forests, and a band of xeric vegetation.

The Aztec mastiff bat is a species of bat in the family Molossidae. It is found from Jalisco and Cozumel Island in southern Mexico to Nicaragua in a variety of forest habitats at elevations from near sea level to 1300 m. It has also been reported from southern Venezuela. The species' diet is insectivorous.

The black mastiff bat is a bat species. It ranges from the northern region of South America, most of Central America and parts of southern Mexico.

The Bonda mastiff bat or Thomas's mastiff bat, is a species of mastiff bat from South and Central America. It is named for the town of Bonda, near Santa Marta in Colombia.

The Coiban mastiff bat is a species of bat in the family Molossidae. Its range extends from Chiapas in southern Mexico to Mato Grosso in Brazil, including Peru, Ecuador, Venezuela, Panama, Costa Rica and El Salvador. The taxonomic status of the populations in Central America is uncertain. The species is insectivorous and is known from a variety of forest habitats at elevations from near sea level to 1300 m.

Miller's mastiff bat is a species of bat in the family Molossidae. It is found in Brazil, Colombia, Costa Rica, Guyana, Mexico, Nicaragua, and Venezuela.

The Sinaloan mastiff bat is a species of bat in the family Molossidae, native to Mexico, Central America and northern South America.

The velvety free-tailed bat or Pallas's mastiff bat, is a bat species in the family Molossidae.