Polaria polaris is a species of sea slug, an aeolid nudibranch, a marine heterobranch mollusc in the family Paracoryphellidae.
Polaria polaris is a flabellinid nudibranch with numerous closely spaced cerata and extremely long rhinophores.
The body is translucent white and the digestive gland in the cerata is red.
There is a broad band of opaque white pigment at the tip of the cerata.
The rhinophores are smooth or slightly wrinkled and the oral tentacles have a splash of white pigment in the outer third.