Wairarapa duplaris is a species of sea snail, a marine gastropod mollusk in the family Drilliidae.

(Original description) The small, solid shell has a lanceolate shape.

Its colour is dull cream, with a faint dorsal zone of brown.

On the earlier part of the body whorl these ribs are smaller and closer together than previously.

Between the suture and the fasciole is a spiral ridge which tends to break up into beads opposite the ribs.