While a growing literature demonstrates the impact of socio-political factors on citizens' quality of life, scholars have paid comparatively little attention to the role political organizations such as labor unions play in this regard. We examine labor organization as a determinant of cross-national variation in life satisfaction across a sample of advanced industrial polities. Our findings strongly suggest that unions increase the life satisfaction of citizens, and that that this effect holds for non-union members as well. Moreover, we also find that labor organization has the strongest impact on the subjective well-being of citizens with lower incomes. We confirm these hypotheses using both individual and aggregate-level data from fourteen nations. We show these relationships to have an independent and separable impact from other economic, political, and cultural determinants. The implications for the study of life satisfaction and of labor unions as political actors in general are discussed.