Mangilia osumiensis G. B. Sowerby III, 1913 (original combination) Anacithara osumiensis is a species of sea snail, a marine gastropod mollusc in the family Horaiclavidae.

Kilburn disputed in 1994 that Mangilia osumiensis should belong to the genus Anacithara, as it shows features that are unknown in Anacithara, such as two vestigial folds on the inner lip.

The shell contains 7 whorls and is distinctly spirally striated.

The wide siphonal canal is curved.

This marine species occurs off the coasts of Japan.