Ethmia galactarcha is a moth in the Depressariidae family. It was described by Meyrick in 1928. It is found on Java, Sumatra, Flores and Sumbawa. The wingspan is 42 mm. The forewings are yellow-whitish with a small black dot on the costa near the base and with the costal edge shortly black beyond this. There are small black basal and subbasal dots in the middle, two towards the costa beyond these, one near the dorsum towards the base, one beneath the fold at one-third, one on the end of the cell and a curved series of four towards the apex and costa. There is also a marginal series of nine rather larger round spots at the apical part of the costa and termen. The hindwings are grey, paler anteriorly and darker and with dark veins towards the apex.