Marine litter is a complex and multifaceted threat necessitating systemic reform and collaborative solutions. Innovation and coordinated action are essential, but interventions must be framed within the Cambodian context and empower local leadership and action. This study focuses on absence of adequate solid waste management (SWM) as a key driver of Cambodia's marine litter & plastic pollution. As such, the study assesses solid waste management (SWM) in the Koh Rong Municipality (KRA) with a focus on its relevance to marine litter and macro-plastic pollution in the Koh Rong Marine National Park (KRMNP). Findings from this assessment have been used to develop a series of policy and onsite recommendations to improve SWM and reduce marine plastic pollution in the KRMNP. This report and its recommendations also speak to broader action under The World Bank’s National Plastics Action Plan and Road Map.