Elachista nearcha is a moth in the Elachistidae family. It was described by Meyrick in 1910. It is found in southern India. The wingspan is 8-9 mm. The forewings are white. The plical stigma is represented by a thick elongate black mark. The second discal stigma by a short fine black dash. There is also an oblique fascia of brownish irroration crossing the before the second discal stigma, and a less marked inwardly oblique fascia from the costal extremity of this across the plical stigma to the dorsum. There is a apical patch of brownish irroration. The hindwings are dark grey.