In this article we examine gender gaps in poverty in the United States and seven other Western nations, asking how single motherhood, market earnings, and welfare states affect gender inequality in poverty. Our analyses speak to the theoretical literature emphasizing the gendered logic and effects of welfare states and labor markets. We find that single-mother families have higher poverty rates than other families in all nations except Sweden, though the degree of their poverty varies. Regarding welfare states, we find that the tax and transfer systems in Sweden and the Netherlands most effectively reduce gender inequality in poverty. Gender inequality in market earnings is worst in the Netherlands and Australia, though among full-time workers, Australia has the lowest gender gap. We conclude by discussing the policy issues raised by our findings.