Elachista bassii is a moth of the Elachistidae family that is found in the north of Nepal. The wingspan is 5–5.5 millimetres (0.20–0.22 in) for males. One third of the forewing, beneath the costa, is occupied by a yellowish white fascia from which bronzy area starts. The ventral side of the wings is brilliant grey. The females are brachypterous.