Parornix polygrammella is a moth of the Gracillariidae family. It is known from Fennoscandia, Estonia, northern Russia and France. The larvae feed on Betula nana. They mine the leaves of their host plant. The mine consists of a small, lower-surface, tentiform mine. After the larva has left the mine, it folds a leaf downwards over the midrib and consumes it up to the epidermis.