Populism is a concept that is currently in vogue among political commentators and is, more often than not, used pejoratively. The phenomenon of populism is typically seen as something adverse and, in the European context, routinely related to xenophobic politics. What populism exactly is, however, and who its representatives across Europe are, often remains unclear. This study has two main aims: to identify populist parties in 21st-century Europe and to explain their electoral performance. It covers long-established Western European countries as well as post-communist countries in Central and Eastern Europe and combines a fuzzy set Qualitative Comparative Analysis (fsQCA) of 31 European countries with three in-depth case studies of the Netherlands, Poland and the United Kingdom. The study shows that the performance of populist parties is to a large extend dependent on their own ability to present themselves as credible alternatives to the established parties.