Volvarina unilineata is a species of sea snail, a marine gastropod mollusk in the family Marginellidae, the margin snails.
The length of the shell attains 14 mm.
(Original description) The shell is fusiform-ovate, attenuated towards the base, milky-white, shiny, and sometimes banded with an orangey-brown line. The spire is conical, the outer lip is flexuous, and the columella is quadriplicate (four-folded).
The shell is white and slightly angulated posteriorly. It possesses an inferior revolving brown band.
This marine species occurs off the Philippines and Hawaii.