Plastic pollution is an urgent and far-reaching crisis that threatens natural systems, wildlife, and human health in every country. In response, nations around the world are currently negotiating a high-level treaty to coordinate plastic-reduction efforts on a global scale. Nevertheless, even if an agreement is reached, no single solution can resolve the crisis alone: addressing plastic pollution will require changes at every stage of production and use, from governments enacting new regulations and businesses transitioning to biodegradable materials, to individual consumers choosing reusable items over single-use products. At the heart of these efforts, individuals and communities will play a uniquely vital role in curbing plastic waste and improving disposal practices. However, for behavior change initiatives to match the scope of the problem, they will have to be guided by robust evidence and best practices. This report examines current approaches, theories, and interventions for reducing plastic pollution and highlights the untapped potential of behavioral and social insights. By bridging the gap between conventional strategies and these powerful tools, it provides actionable, science-based recommendations for practitioners and policymakers.