The UN General Assembly and the UN Environment Assembly (UNEA) have expressed concerns about the pollution of the sea by plastics, which adversely impacts ecosystems, some economic activities (e.g., tourism and fishing), and possibly public health (e.g., consumption of contaminated fish). In December 2017, the UNEA decided to establish the Ad Hoc Open-Ended Expert Group on Marine Litter and Microplastics to examine ways to combat marine plastic pollution. The group met three times in 2018 and 2019, and at least two more meetings are planned. Among potential responses to the issue of marine pollution, the group briefly considered—but eventually dismissed—the possibility of creating a liability or compensation regime. This essay evaluates the prospects for such a regime. As the essay will show, compensation faces significant conceptual problems, not the least of which is the absence of an obvious recipient. However, some form of liability could be imposed on corporations that produce plastic, or on states that fail to regulate them. Such a liability regime, even without financial compensation, could foster the prevention of further marine plastic pollution.