Pseudoliva sepimentum is a species of sea snail, a marine gastropod mollusk in the family Pseudolividae.

The ovate, conical shell is slightly ventricose, attenuated at summit and base, pretty solid and nearly smooth.

Its ground color is bluish ash, ornamented with a deeper band upon each whorl, and upon the lowest, with two others, distant, and more obvious.

The aperture is whitish, ovate, elongated, and terminates at the base by a very oblique emargination, and above by a canal formed by the prolongation, upon the columella, of a callosity which becomes there a thin sharp plate.

From the middle arises a ridge which descends obliquely nearly to the base of the outer lip, where it terminates within by a small elevation.