Negative out-group attitudes are often attributed to perceptions of competition or threat. We propose an alternative source: culture, conceptualized as cultural scripts—interconnected networks of meanings that link particular group identities to negatively connoted phenomena. Evidence comes from three studies on the reactivation of the cultural script of traditional antisemitism in Germany. We begin our analysis by isolating the cultural script through automated analysis of a corpus of antisemitic texts. Next, using survey data collected during the COVID-19 pandemic (n = 17,800), we document an increase in antisemitism among Christian believers. This, we argue, is due to the pandemic activating the cultural script of traditional antisemitism, which links Judaism with the spread of disease. By means of an additional survey (n = 2,000) and a concept association task, we demonstrate the presence of the cultural script in the minds of Christian believers. Two priming experiments explore how elements of the script can be triggered. Our work demonstrates the deep cultural roots of negative out-group attitudes and suggests a novel set of methods for studying them.