Recent decades have witnessed an upsurge in activism around labor issues in global production networks. A particularly prominent example is the antisweatshop movement, a diverse collection of efforts to promote labor rights and improve working conditions in international supply chains for apparel and footwear products. Much of the literature on the antisweatshop movement emphasizes its global nature and the reliance of activists on transnational advocacy networks involving coalitions of Northern (usually U.S.-based) consumers and Southern workers. Drawing theoretical inspiration from the varieties of capitalism literature, we examine instead the emergence and institutionalization of antisweatshop politics within the global North. Based on interviews with groups in eight countries, we analyze the trajectories of antisweatshop activism in Western Europe, the United States, and Canada, finding marked variation in the leadership and composition of the movement across regions. Antisweatshop politics were particularly contentious in the United States, where labor leaders were active in framing the sweatshop scourge as a domestic as well as an international social problem. In Europe and Canada, the key role was played not by organized labor, but by other civil society groups that encouraged a multistakeholder approach to what was perceived primarily as an issue of social and economic development in the global South. Overall, our analysis highlights how national institutions and political cultures shape the way that actors assess a social problem and evaluate the possibilities available to effect meaningful change.