Within the current study, we address the question of whether intelligence would be negatively related to narcissistic identity with nation (i.e., belief in the nation's greatness that requires external recognition) and endorsement of conspiracy theories (i.e., the tendency to explain events through secret plots by powerful groups). We found a consistent pattern of associations using the data from two culturally different samples of Polish (N = 1143) and British (N = 388) participants. That is, we observed consistent negative relationships between intelligence and socio-psychological variables responsible for out-group derogation: national narcissism and conspiracy beliefs. Moreover, lower national narcissism partially accounted for the association between higher intelligence and lower conspiracy beliefs, which provides initial evidence that higher intelligence may be related not only to a less narcissistic identity but also to weaker endorsement of conspiracy theories. We discuss the implications for understanding the role of intelligence and national narcissism in shaping the psychological roots of susceptibility to conspiracy narratives.