Lecithocera nefasta is a moth in the Lecithoceridae family. It was described by Meyrick in 1916. It is found in southern India. The wingspan is about 21 mm. The forewings are dark purplish-fuscous. The discal stigmata are represented by small obscure darker spots, the first round, the second transverse-oval. The hindwings are grey, darker towards the apex.