See text Fionidae is a family of sea slugs, aeolid nudibranchs, marine gastropod molluscs in the superfamily Fionoidea.

[1] This family was expanded to include Tergipedidae, Eubranchidae and Calmidae as a result of a molecular phylogenetics study.

[2] This was reversed in 2017 with further DNA evidence and a re-interpretation of genus and family characteristics.

[3] Genera within the family Fionidae include: