Ethalia polita is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
The white, solid, semi-opaque shell has an orbiculate-conoidal shape. The whorls are almost conical and the base is convex containing a large callus. The whorls are obsoletely transversely striated. The round aperture has a continuous peristome.
This marine species occurs off Japan.