ABSTRACTTax morale, commonly measured as a moral evaluation of cheating on taxes, is important for shaping policy to increase voluntary compliance. Although tax morale is commonly understood as citizens' moral responsibility to pay taxes, there is a dearth of empirical research on whether and how differences in basic morality shape tax morale. Three studies investigated associations between moral ideals, as defined by Moral Foundations Theory, and tax morale. Study 1 (N = 103,474; 57 countries) examined how national differences in moral foundations predict individuals' tax morale. Study 2 (N = 1019) and Study 3 (N = 1001) focused on individual‐level differences. All studies employed multiverse analyses, iterating through multiple combinations of control variables. Despite the apparent semantic similarities between morality and tax morale, consistent empirical connections emerged only with respect to individualising foundations, in particular, fairness. Findings provide first evidence for the role of morality in tax morale, while contributing to a better understanding of why people pay taxes.