Stigmella leucargyra is a moth of the Nepticulidae family. It is only known from the south-eastern coast of New South Wales, Australia. The wingspan is about 3.7 mm for males and 4-4.2 mm for females. The larvae feed on Correa reflexa. They mine the leaves of their host plant. The mine consists of an irregular contorted gallery in the leaf. Larvae where found in July and August. Adults emerged in early September. The larvae are bright green with a blackish head.