Monalocoris filicis is a true bug in the family Miridae. The species is found in Europe from Ireland in the West and including the northern edge of the Mediterranean and the East across the Palearctic to Central Asia, Korea and Japan. In Central Europe, it is widespread and generally common. In the Alps, it occurs up to the edge of the forest. Habitats are deciduous and coniferous forests and moist, open habitats such as bogs or the shores of streams.