AbstractObjectivesDespite the broad appeal of abstract notions of political tolerance, people vary in the degree to which they support the political rights of groups they dislike. Prior research highlighted the relevance of individual differences in the cognitive domain, claiming the application of general tolerance ideals to specific situations is a cognitively demanding task. Curiously, this work has overwhelmingly focused on differences in cognitive style, largely neglecting differences in cognitive ability, despite compelling conceptual linkages. We remedy this shortcoming.MethodsWe explore diverse predictors of tolerance using survey data in two large samples from Denmark (N = 805) and the United States (N = 1,603).ResultsCognitive ability was the single strongest predictor of political tolerance, with larger effects than education, openness to experience, ideology, and threat. The cognitively demanding nature of tolerance judgments was further supported by results showing cognitive ability predicted tolerance best when extending such tolerance was hardest. Additional small‐sample panel results demonstrated substantial 4‐year stability of political tolerance, informing future work on the origins of political tolerance.ConclusionsOur observation of a potent role for cognitive ability in tolerance supports cognitively oriented accounts of tolerance judgments and highlights the need for further exploration of cognitive ability within the political domain.