The Northern Wall Brown (Lasiommata petropolitana) is a butterfly species belonging to the family Nymphalidae. It can be found in large parts of Europe, from the Pyrenees and Alps up to Scandinavia and Finland, up to Russia and Siberia. The males are 19–21 mm. The butterflies fly in one or two generations from April to September. The larvae feed on various grasses, mainly Dactylis glomerata, Festuca rubra and Festuca ovina .