Mysidae is the largest family of crustaceans in the order Mysida, with over 1000 species in around 170 genera.

Members of the family Mysidae are distinguished from other mysids by the fact that the first pereopod (walking leg) has a well-developed exopod (outer branch), the carpopropodus of the endopod (inner branch) of the 3rd to 8th pereopods is divided into sub-segments and there are statocysts on the endopod of the uropods (posterior appendages). Female petalophthalmidans have two or three oostegites (flexible bristly flaps) forming the base of the marsupium or brood pouch under the thorax, apart from the subfamily Boreomysinae, which has seven pairs of oostegites.

The following subfamilies and genera are recognised: