Fluorescence induced by ultraviolet light has been observed in many animals, from invertebrates to mammals. Fluorophores (chemical compounds responsible for fluorescence) have been studied in feathers of bird species; for example, porphyrins (one of the most abundant biological pigments) in feathers of some owl species produce red-orange fluorescence. We conducted a fluorescence study on 13 European owl species, and found fluorescence in all of them. Contrary to what was previously reported, we also found fluorescence in the snowy owl (Bubo scandiacus). We also investigated fluorescence of different body and feather areas of the owls, and found similarities between species and some differences depending on occupied landscape, nest and life type, activity period, and plumage colour.