Lethrinus variegatus was first formally described in 1830 by the French zoologist Achille Valenciennes with its type locality given as Massawa in Eritrea.

[4] Lethrinus variegatus has the specific name vatiegatus which means "variegated", Valenciennes did not explains this but it may be an allusion to the varied pattern of black spots on the flanks.

There are frequently two dark bars underneath the eye, one extending to the lower margin of the preoperculum and the other to the corner of the mouth.

It is found along the eastern coast of Africa from the Gulf of Suez and Gulf of Aqaba south to Sodwana Bay in South Africa, in the Comoro Islands, Seychelles, Madagascar, the Chagos Islands, southern India and Sri Lanka, east around the Malay Archipelago into the Pacific Ocean where it is found as far north as the Ryukyu Islands, south to Australia and New Caledonia and east to Tonga.

[1] The slender emperors lives in sandy and weedy areas close to coral reefs, singly or in small schools.