Abstract: Conspiracy mentality (CM), the general propensity to believe in conspiracy theories, has been linked to political behaviors, prejudice, and non‐compliance with public health guidelines. While there is increasing evidence that conspiracy beliefs are pervasive, research on individual‐level predictors of CM is scarce. Specifically, we identify three gaps in research: First, evidence on the question which individual‐level characteristics predict CM is inconsistent and often based on small samples. Second, personality, political, and religious predictors are usually examined in isolation. Third, differences on the societal level have been mostly neglected. In the present research, we gathered CAWI (Study 1) and CATI (Study 2) data on generalized interpersonal trust (GIT), right‐wing authoritarianism (RWA), and religiosity in two politically and culturally different European countries, namely Germany (N = 2,760) and Poland (N = 2,651). This allowed for a well‐powered test of three theoretically relevant predictors of CM, including their unique predictive value. Moreover, we were able to explore whether these associations replicate across or are moderated by country context. Our findings underline the role of GIT and RWA in predicting CM in both countries. Analyses based on RWA subdimensions yielded a differentiated picture of the role of RWA. Furthermore, we found cross‐country differences with stronger associations of GIT and RWA with CM in Germany. Findings are discussed concerning political and religious differences between the examined countries.