Plastics revolutionized our world, but their unforeseen effects are accelerating many ecological and social crises--polluting both our oceans and our politics. Plastic Legacies gathers scholars of marine biology, psychology, anthropology, environmental studies, Indigenous studies, and media studies to investigate the urgent socio-ecological challenges exacerbated by plastics. Rejecting neoliberal solutions, the contributors argue that collective action is key to securing lasting change.