 The study examines predictors of belief in COVID-19 misinformation across five national samples from the UK, Ireland, USA, Spain, and Mexico, finding that while public belief in such misinformation is not common, a substantial proportion views it as highly reliable. Increased susceptibility to misinformation negatively affects people's self-reported compliance with public health guidance about COVID-19, as well as their willingness to get vaccinated against the virus and recommend it to vulnerable friends and family. Higher trust in scientists and having high enumeracy skills were associated with lower susceptibility to coronavirus-related misinformation, suggesting that interventions aimed at improving critical thinking and trust in science may be a promising avenue for future research. This article was authored by John Rosenbeek, Claudia R. Schneider, Sarah Dryhurst, and others.