Leiocithara porcellanea is a species of sea snail, a marine gastropod mollusk in the family Mangeliidae.
The length of the shell attains 9.1 mm, its diameter 3.8 mm. It is closely related to Leiocithara lischkei <small>(E. A. Smith, 1888)</small> from Japan, but otherwise it displays shell characters of both Leiocithara and Citharomangelia.
This species occurs off Zululand, South Africa, at depths between 75 m and 160 m.