Eudarcia richardsoni is a species of moth in the Tineidae family.
This species is thought to be endemic to Britain, restricted to few localities on Portland, which is located in southern Dorset, and known from no-where else in the world. This species inhabits sea cliffs, where the larva can be found in a larva case, which is made from lichens and rock fragments. The adult moths, flying in Summer, are black with several white stripes. The first white stripe is complete, while the second is split in two, and the third only passes through half the wing.