Idotea neglecta is a marine isopod in the family Idoteidae. It can be found on algae in the littoral and sublittoral zone of north-west European coasts.
I. neglecta can be found on all north-west European coasts.
Male I. neglecta measure , females . They are brownish, sometimes with white longitudinal lateral markings or white marbling over the dorsal surface. The pleotelson of adults has straight sides converging posteriorly.