We predicted that the relationship between helping strangers and life satisfaction would depend partially on the wealth of the country in which one lives. We argue that wealthy societies provide a wide range of welfare provisions for assisting their citizens. By contrast, people living in poorer countries with associated lower individualism, lower generalised trust, and higher religiosity have fewer financial and institutional supports for their daily welfare. They thus receive greater personal and interpersonal rewards for helping strangers in their societies and experience greater life satisfaction. Using a 137-country sample, we found that the relationship between helping strangers and life satisfaction was weaker in wealthier nations and in nations with more individualistic, more trusting, but less religious citizens. When all four moderators were used, only trust and religiosity remained significant moderators. In a supplementary mediated moderation model, we also found that trust and religiosity mediated the effect of national wealth on the relationship between kindness and life satisfaction. We conclude that the relationship between kindness and life satisfaction depends on various aspects of national culture that may reduce or increase people’s dependence in their daily lives on the help of others as opposed to dependence on welfare institutions.