Phyllonorycter pygmaea is a moth of the family Gracillariidae. It is known from Japan (the islands of Hokkaidà Â, Kyà «shà «, Shikoku and Honshà «), Korea and the Russian Far East.
The wingspan is 5-5.5 mm.
The larvae feed on Castanea crenata, Quercus acutissima, Quercus crispula, Quercus mongolica and Quercus serrata. They mine the leaves of their host plant.