Phyllonorycter martiella is a moth of the Gracillariidae family. It is known from British Columbia, Nova Scotia and Québec in Canada and Maine, Michigan, North Carolina, Vermont and Kentucky in the United States. The wingspan is about 6.8 mm. The larvae feed on Betula species, including Betula lenta. They mine the leaves of their host plant. The mine has the form of an elongated mine on the underside of the leaf.