Cultural boycotts of mega-events often receive high media profile, but their effectiveness remains questioned. This effectiveness is influenced by their ability to generate ontological insecurity within the target state. However, measuring the impact of such threats is challenging in light of the evasive nature of the concept of ontological insecurity. Hence, we advance a new way to operationalize the impact of both hosting and boycotting mega-events on ontological security (OS), using quantitative indicators on the societal level, thus allowing for a more systematic cross-national exploration of the dynamics of OS. We also contribute to the research on cultural sanctions and the politics of mega-events, by offering an empirical assessment of their actual impact on society’s sense of OS. Finally, the paper points to the importance of de-constructing the concept of ‘national’ ontological (in)security and to the possibility that different segments in society may be more or less vulnerable to such threats. Using data from a national-wide survey among Jewish-Israelis in the context of the 2019 Eurovision Song Contest in Israel, we found a positive association between its hosting and OS, a perception of threat to OS to some extent following calls to boycott the event, and differences in these perceptions among various social groups.