Kentrocapros spilonotus was first formally described as Aracana spolinota in 1905 by the American ichthyologist Charles Henry Gilbert with its type locality given as Albatross station 3939 near Laysan Island in the Leeward Islands of Hawaii from a depth between 59 and 163 fathoms (354 and 978 ft; 108 and 298 m).

[4] The 5th edition of Fishes of the World classifies the genus Kentrocapros in the family Aracanidae which is in the suborder Ostracioidea within the order Tetraodontiformes.

The specific name, spilonotus, means "spot-backed" and refers to the brownish-green spotting on the back and upper bodty ofthis fish.

There is a stiffcarapace which covers all of the body except the caudal peduncle, gill slit and the bases of the fins.

The preserved specimens are brown in colour with numerous darker spots on the upper carapace with pale fins.