Previous research has demonstrated that higher levels of belief in conspiracy theories are related to higher levels of distrust toward others, greater antisocial tendencies, and more self-centeredness. These findings suggest that conspiracy believers may also be less likely to be generous. However, very little research has thus far investigated this possibility. In the current study, we examined the association between COVID-19 conspiracy beliefs and generosity across a sample of 45,073 participants from 52 countries. We found that participants with higher COVID-19 conspiracy beliefs were less likely to donate to national and international charities, and that this negative association was stronger for donations to national charities. Exploratory analyses revealed that the discrepancy between national and international charity donations was more salient in countries with high levels of corruption, suggesting that conspiracy believers might be more suspicious of ingroups, rather than outgroups, in more corrupt countries.