Elachista nitensella is a moth in the Elachistidae family. It was described by Sinev and Sruoga in 1995. It is found in Japan (Hokkaidô, Honsyû, Kyûsy) and the Russian Far East (Primorsky Kray). The length of the forewings is 2.9–3.7 mm for males and 3.6–3.7 mm for females. The forewings are blackish, slightly shiny and with gold-silvery markings. Adults have been recorded on wing from in July, probably in one generation per year. The larvae feed on Carex species, possibly including Carex microtricha. They probably feed on the roots of their host plant.