It is widely spread across the African tropical rainforest.

The western dwarf hornbill was formally described in 1861 by the English ornithologist John Gould based on a specimen from "Western Africa".

Gould coined the binomial name Toccus hartlaubi.

The specific epithet was chosen to honour of the German ornithologist Gustav Hartlaub.

[4] It is black with a curved beak and a wide white brow above its eye.