Serrata tuii is a species of sea snail, a marine gastropod mollusc in the family Marginellidae, the margin snails.Like other members of its genus, it is characterized by a glossy, polished shell and a highly specialized anatomy adapted for life in deep-water marine environments.
The size of the shell of a Serrata tuii sea snail reaches 10 mm, this shell has a distinct shiny outer surface.
This marine species occurs off New Caledonia.