Erythromma najas (Large Redeye) is a northern palaearctic damselfly species. Its geographical range reaches from France and the southern UK to northern Japan. It is absent from Iberia and rare and scattered in Italy and the Balkan.
Large Redeyes prefer eutrophic to mesotrophic standing or slow-flowing waters with a well-developed submerse vegetation. Territorial males are often seen perched on floating leaves of waterlilies (Nymphaeaceae).