It is thought that the name refers to Achilles, the mythical hero of the Trojan War, and may be an allusion to the sharp bony plates on the caudal peduncle.

[6] Acanthurus achilles has an elongated oval-shaped body with a steep dorsal profile to the head.

The small, protrusible mouth is positioned low on the head with between 8 and 28 teeth fixed on each jaw, each having a flattened, serrated tip.

The overall colour is bluish-black with an irregular oval orange blotch on the rear of the body, a white bar on the gill cover, a wide orange bar on the caudal fin which also has a white posterior margin.

[2] Acanthurus achilles is found in various reefs of Oceania, up to the islands of Hawaii and Pitcairn.