Unsustainable production and consumption patterns of single use plastics are causing worldwide negative environmental and socioeconomic impacts on land-based and marine ecosystems. Nevertheless, in Latin America, plastics governance is still fragmented across borders because of dispersed normative adoption and limited regional coordination. In this context, the instrumental level of articulation between the international principles of environmental law and the formal legal arrangements from the Pacific Alliance countries is assessed to analyze how this strategic platform can contribute to offering a regional response to the global problem of single use plastics. For this purpose, an illustrative case study of the national and subnational regulation developed by the Pacific Alliance and its members was performed. To this end, a framework analysis was conducted on the official legal documents from Mexico, Colombia, Chile, Peru, and Ecuador. The results show extensive and scattered subnational regulation to control the consumption of plastic bags and single use plastics, with diverse policies on extended producer responsibility, educational and economic strategies to influence mainly the consumer’s behaviour. Recommendations are presented in order to improve plastics governance in the region through the legal component.