Elachista ribentella is a moth of the Elachistidae family. It is found in Japan and the Russian Far East. The length of the forewings is 2.7–3.5 millimetres (0.11–0.14 in) for males and 3.5–3.7 millimetres (0.14–0.15 in) for females. The forewing ground colour is mottled grey, with four indistinct mottled whitish markings. The hindwings are grey. The larvae feed on Carex blepharicarpa. They mine the leaves of their host plant.