Nanula tasmanica is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails[1] The height of the shell attains 6 mm, its diameter 5.5 mm.

It is lusterless, whitish, tinged with yellow or greenish, unicolored or marked with a few angular radiating maculations of blackish-brown.

The aperture is quite oblique, rounded-ovate, angular above, broadly rounded below, with a thin iridescent layer of nacre within.

[2] This dull whitish little shell may be known by its finely striate surface, narrow umbilicus, short spire and globose-turbinate form.

This marine species is endemic to Australia and occurs in the shallow subtidal zone off Tasmania, Victoria and in the Bass Strait.