The deepbody boarfish was first formally described in 1843 by the English zoologist Richard Thomas Lowe with its type locality given as Madeira.

[4] The 5th edition of Fishes of the World classifies the genus Antigonia in the Antigoniinae, a subfamily of the Caproidae, within the order Caproiformes,[5] as do other authorities.

[8] The deepbody boarfish has a highly compressed, rhomboid shaped body with convex dorsal and ventral profiles.

The small head bears bony ridges that radiate, has a concave dorsal profile and a clear crest along the nape.

The eyes are large and the mouth is small, upward pointing, opens at the front and has protrusible jaws.