Microplastic contamination in the environment continues to receive global attention, with calls for the synthesis of scientific evidence to inform actionable strategies and relevant policies. An increasing number of organisations are undertaking research, monitoring, and data collection on plastic contamination in marine environments, but disparate sampling, analysis, and reporting methods limit dataset comparability and integration. This restricts global insights into microplastic occurrence, effects, and dynamics, and reduces our ability to establish indicators for monitoring and decision-making. This session will focus on global approaches to monitor microplastics, examining the challenges and successes in harmonising sampling protocols across regions, and developing best practices that can be used by a range of stakeholders, including research institutions, NGOs, and government agencies. We aim to explore how learnings from different regions across the world can be combined to support a unified approach to microplastic monitoring. By leveraging multidisciplinary approaches and cross-sector engagement, this session aims to further promote and solidify the implementation of best practices for microplastic monitoring and assessments worldwide.