Vexillum gruneri is a species of small sea snail, marine gastropod mollusk in the family Costellariidae, the ribbed miters.

(Original description) The shell is shortly fusiform, somewhat harpshaped.

The shell is olive-green, painted in the interstices between the ribs with three rather distant transversc reddish-brown lines.

[2] The shell is white, more or less distinctly banded with ash, with a superior, and sometimes one or two inferior narrow chestnut revolving lines.

[3] This species occurs in the central Indo-West Pacific; also off Papua New Guinea, New Caledonia and Australia (Queensland).