Prothalotia lesueuri, common name Lesueur's top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

The somewhat solid, imperforate shell has an elongated conical shape.

It is whitish or a little tinged with olive, painted with numerous rather narrow longitudinal olive-brown or reddish-brown stripes generally broken into tessellations on the base.

The body whorl is a trifle deflexed at the aperture and is often subangular at the periphery.

The rhomboidal aperture measures less than half the total length of shell.