Ethmia nobilis is a moth in the family Depressariidae. It was described by Alexey Diakonoff in 1968. It is found on Luzon in the Philippines.
The wingspan is about . The forewings are glossy, light slate grey with a faint purplish hue. The markings are black, faintly edged with whitish. There are also three elongate plical dots, becoming larger posteriorly. There is also a larger oval spot in the cell in the middle of the wing and three subapical dots, as well as a row of eleven marginal dots. The hindwings are glossy light grey fuscous, the basal fourth as far as the lower edge of the cell whitish.