Aristotelia themerastis is a moth of the family Gelechiidae. It was described by Alfred Jefferis Turner in 1919. It is found in Australia, where it has been recorded from New South Wales.[1]
The wingspan is 12–13 mm. The forewings are pale-grey irrorated with darker grey and with four fuscous discal dots, often partly obsolete, the first at one-third, the second on the fold obliquely beyond the first, the third at two-thirds and the fourth beneath and beyond the third. There is a slight blackish irroration at the apex and along the termen. The hindwings are grey-whitish.[2]