Populism is on the rise, especially in Western Europe. While it is often assumed that populist actors have a tendency for fallacious reasoning, this has not been systematically investigated. We analyze the use of informal fallacies by rightwing populist politicians and their representation in the media during election campaigns. We conduct a quantitative content analysis of press releases of rightwing populist parties and news articles in print media during the most recent elections in the United Kingdom and Switzerland in 2015. The results show that fallacies are used in more than a third of all analyzed texts and overwhelmingly cooccur with populist key messages. Moreover, fallacies occur more often in Populist parties’ press releases than in news articles and are more common in Switzerland compared to the United Kingdom. This study confirms the argument that Populist actors use fallacies in combination with Populist claims.