This article develops the notion of sustainable citizenship and distinguishes it from more conventional forms of citizenship. The authors formulate indicators of the presence of sustainable citizenship among individuals, in corporations, and in nongovernmental organizations and apply those indicators in two empirical studies. The first study is of institutions (Fairtrade International, People for the Ethical Treatment of Animals, and The Walt Disney Company), and the second is of individuals, particularly those who practice political consumerism and vegetarianism. The studies show that citizenship is expanding in three significant ways: by addressing concerns about past and current injustices and their effects on the future (broadened temporal dimension); by addressing responsibilities worldwide, not just within one's country (broadened spatial dimension); and by adding a material dimension that emphasizes responsibility to nature and animals. The studies find that the development of sustainable citizenship is taking detours. In particular, self-interest often dominates its nonreciprocal or other-regarding concerns.