Elachista sapphirella is a moth of the Elachistidae family. It is found in south-eastern New South Wales, the Australian Capital Territory and Victoria. The wingspan is 4.7–6.2 millimetres (0.19–0.24 in) for males and 6.4 millimetres (0.25 in) for females. The forewings are bluish grey for males and dark grey with four white markings for females. The hindwings are grey. Larvae have been reared from an unidentified Poaceae species.