Elachista catarata is a moth of the Elachistidae family that can be found in eastern New South Wales, the Australian Capital Territory and Tasmania. The wingspan is 7.8–8.8 millimetres (0.31–0.35 in) for males and 7.8–9.5 millimetres (0.31–0.37 in) for females. The forewings are dark bluish grey. The hindwings are dark grey.