Chromodorididae, or chromodorids, are a taxonomic family of colourful sea slugs; dorid nudibranchs, marine gastropod mollusks in the superfamily Doridoidea. "Chromodorid nudibranchs are among the most gorgeously coloured of all animals." The over 360 described species are primarily found in tropical and subtropical waters, as members of coral reef communities, specifically associated with their sponge prey. The chromodorids are the most speciose family of opisthobranchs. They range in size from <10mm to over 30 cm, although most species are approximately 15–30 mm in size.

Although, they have a worldwide distribution, most species are found in the Indo-Pacific region. A scientific paper published in 2007, found the most widespread chromodorid genera, (Mexichromis, Chromodoris, Glossodoris and Hypselodoris) to be paraphyletic or polyphyletic.

The family Cadlinidae Bergh, 1891 has been considered a synonym of the Chromodorididae. Research by R.F. Johnson in 2011 has shown that Cadlina does not belong to the family Chromodorididae. She has therefore brought back the name Cadlinidae from synonymy with Chromodorididae. The chromodorid nudibranchs without Cadlina are now monophyletic and turn out to be a possible sister to the family Actinocyclidae. Cadlina and Aldisa are the only two genera currently classified in the Cadlinidae.

A comprehensive phylogeny of the chromodorid nudibranchs found every one of the 14 traditional chromodorid genera were either non-monophyletic, or rendered another genus paraphyletic. Additionally, both the monotypic genera Verconia and Diversidoris are nested within clades. The authors presented a new classification of the chromodorid nudibranchs, which used molecular data to untangle evolutionary relationships and at the same time retains a historical connection to traditional systematics by using generic names attached to type species as clade names. All Chromodorid nudibranchs feed on sponges.

...