The fishes in this genus are found in the Indian and western Pacific Oceans.

Monotaxis was first proposed as a genus in 1830 by the author of the section on zoological specimens in the Memoir of the life and public services of Sir Thomas Stamford Raffles when that author described Monotaxis indica from Sumatra.

The family Lethrinidae is classified by the 5th edition of Fishes of the World as belonging to the order Spariformes.

There are round, flat molar-like teeth in the sides of the jaws and the maxilla has a horizontal serrated ridge along its outer surface.

They are usually found near coral reefs over areas of sand and rubble at depths between 3 and 150 m (9.8 and 492.1 ft).