Theorists have suggested that faith in God can play an important role in the relief of anxiety associated with uncertainty. Yet little is known about the impact of national differences in uncertainty avoidance – the degree to which uncertainty is threatening to members of a culture – on the relationship between faith and subjective well-being. Inthe present study we investigated faith’s relationships with psychological well-being in the World and European Values Surveys for nearly 240000 people in 92 countries and the role national uncertainty avoidance plays in modifying these relationships. We found that faith was positively related to subjective well-being around the world overall but this relationship was moderated by uncertainty avoidance. In particular the relationship between faith and wellbeing was strongest in nations characterized by the highest levels of uncertainty avoidance. Our results suggest that cultural norms of uncertainty avoidance play a role in determining faith’s role in psychological functioning.