The so-called refugee crisis and the fear of Islamist terror have turned out to be serendipitous for right-wing populist parties. They portray themselves as defenders of the ‘Christian Occident’ and campaign against an ‘invasion of Muslims’ that was allegedly orchestrated by cosmopolitan elites of the EU. Against this backdrop, this chapter explores the linkage between anti-Muslim sentiments and Eurosceptic attitudes. The study shows that (1) there is a pan-European nexus between Islamophobia and Euroscepticism, (2) there is a nexus that is primarily driven by voters of right-wing populist parties and (3) the magnitude of Islamophobic attitudes differ, however, between societies. An anti-Muslim social climate is particularly widespread in Eastern Europe, where hardly any Muslims live. The contribution addresses the resulting implications for the legitimacy of the EU.