There are differing perspectives on the roles that social-perceptual and individual-difference factors play in explaining susceptibility to misinformation. With quota-representative samples from the U.S. (n = 492), the U.K. (n = 600), Poland (n = 558), and Germany (n = 490), we ran a comprehensive test of four social-perceptual factors (i.e., social trust, institutional trust, relative deprivation, and perceived area unsafety) and six individual-difference factors (i.e., narcissism, conspiracy mentality, closed-mindedness, need for predictability, need for order, and perceived locus of control). In terms of the social-perceptual factors, social trust and perceptions of area unsafety were consistently related to higher misinformation susceptibility across countries. In terms of individual-difference factors, narcissism and conspiracy mentality were associated with increased susceptibility to misinformation in three of the four countries. Relative deprivation and external locus of control were related to misinformation susceptibility in the pooled sample. We discuss societal implications of these findings and highlight directions for future research.