The Cliopsidae, common name sea angels, are a taxonomic family of small, free-swimming sea slugs, pelagic marine opisthobranch gastropod mollusks in the order Opisthobranchia.
As is the case in all gymnosome pteropods, these sea angels lack a shell except during an early embryonic stage.
The small lateral wing-like flaps (parapodia) are used in a slow swimming mode. The foot is reduced to three small median lobes.
There are two monotypic genera recognised in the family Cliopsidae:
Genus Cliopsis <small>Troschel, 1854</small>
Genus Pruvotella <small>Pruvot-Fol, 1932</small>