After persecution and a long period of extinction in parts of central Europe, the European wildcat is currently increasing its range, also to areas deemed unsuitable for this species. This range expansion facilitates close contact with domestic cats, which can reach high population densities even in protected areas. We provide unambiguous evidence that the European wildcat is present in the Bavarian Forest National Park. We assessed the frequency of domestic cat occurrence, and analyzed the distributions of the two felid subspecies with regard to residential areas, forested habitat, elevation and protected areas, and analyzed their spatial overlap. Camera traps installed in the national park detected six putative wildcats in 2008–2015 at elevations between 800 and 1100 m a.s.l. Genetic analysis of material obtained from hair traps with valerian-treated lure sticks confirmed the presence of three wildcat individuals in early 2015. The number of wildcat events detected increased slightly in recent years and wildcats were detected closer to shrub cover and the forest edge. Of the domestic cat events, 90% were within 1.1 km of residential areas, but some moved up to nearly 3 km into the national park. Ranges of wildcats and domestic cats broadly overlapped. All but one camera trap that recorded wildcats also recorded domestic cats, and some camera traps recorded domestic cats but no wildcats. Domestic cats were the fifth most often detected mammal species in the protected area. To avoid a negative impact of domestic cats on wildcats through hybridization, which might already occur, and considering the ecological impact of predation by domestic cats, we recommend a buffer zone of 1 km surrounding the national park, where domestic cats should not be allowed outdoors.