Phidiana hiltoni is a species of sea slug, an aeolid nudibranch, a shell-less marine gastropod mollusc in the family Facelinidae.

[1] This species has a rather limited range of distribution, being found from the central California coast to Baja California, Mexico, and it is also found in the Gulf of Mexico.

This nudibranch grows to 50 mm, or a little more than 2 inches in length.

The reddish or brownish line across its head is almost always present, and is very characteristic of the species.

This species can be confused with Hermissenda crassicornis, which is superficially similar in appearance.