<p>Over the last decades, plastic pollution has predominantly been considered a downstream issue, focusing on marine litter and waste management challenges. However, this limited focus is insufficient in responding to the urgency, complexity and scale of the problem. Therefore, the scientific community increasingly calls for a systemic focus on plastic pollution, especially with respect to designing effective policy interventions. Extant literature has documented examples of science-based policy, showing that systems tools have successfully informed policies targeting plastic pollution. With a potentially first, global plastics treaty currently under negotiations, we analyse the way in which systems-based techniques are used in literature to generate evidence regarding plastic pollution and to inform policy processes. We systematically select 324 publications from the systems-based plastic pollution literature and analyse trends, patterns and context in which systems analysis tools are used. We find that the application of these tools is limited and still highly focused on the downstream impacts of plastics. Thus, we make two key recommendations for harnessing systems analysis techniques to strengthen the efforts at developing an ambitious, science-based treaty: the employment of an emitter perspective and supporting a just transition through systems literature.</p>