Phyllonorycter agilella is a moth of the Gracillariidae family. It is found from Latvia and central Russia to the Pyrenees, Italy and Bulgaria and from France to eastern Russia. The larvae feed on Ulmus glabra, Ulmus laevis and Ulmus minor. They mine the leaves of their host plant. They create a lower-surface (but sometimes upper-surface), weakly folded tentiform mine. The folded side of the mine is whitish. The pupa is created in a very loose cocoon.