Calthalotia mundula is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

It is whitish, obsoletely painted with longitudinal purplish flammules.

At the sutures they show a prominent rounded ridge, transversely lirate.

The base of the shell is concentrically lirate, with radiating striae in the interstices.

The arcuate lip ends anteriorly in an obtuse tooth.