Alderia is a genus of sea slugs, marine gastropod mollusks in the family Limapontiidae.

These are sacoglossan sea slugs.

The name Alderia first appeared in Thompson's 1844 Report on the fauna of Ireland[2] as a nomen nudum (Allmann MSS).

Species within the genus Alderia include:

This Limapontiidae-related article is a stub.