Prothalotia flindersi, common name the Flinders top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.

The rather thick, very narrowly perforate shell has a conical shape.

The first one is eroded, the succeeding are whitish-ashen, radiated with narrow, close and flexuose blackish and violaceous lines.

The body whorl is subangular, a little depressed above, dilated in the middle.

The base of the shell is convex and ornamented with about 8 lirae.