Microplastic pollution is an emerging global concern due to its persistence, ubiquity, and potential ecological and socioeconomic impacts. Indonesia, as the world’s largest archipelagic nation with extensive coastlines, diverse ecosystems, and high population density, is particularly vulnerable to marine microplastic contamination. This review synthesizes recent research on the sources, distribution, ecological consequences, and human and socioeconomic implications of microplastics in Indonesian waters, highlighting research gaps and future directions. Microplastic inputs originate from land-based sources, including domestic waste, urban runoff, rivers, tourism, aquaculture, and fisheries, as well as sea-based sources, such as fishing gear, shipping, coastal industries, and offshore aquaculture. Their transport is influenced by hydrodynamic processes, including tides, currents, monsoonal winds, and the Indonesian Throughflow, leading to spatial and seasonal heterogeneity in surface waters, sediments, and biota. Ecological impacts include ingestion by fish and invertebrates, trophic transfer, and interaction with chemical pollutants such as heavy metals and persistent organic pollutants, posing risks to marine biodiversity and ecosystem functioning. Human and socioeconomic consequences arise from seafood contamination, health risks, fisheries and aquaculture productivity losses, and impacts on tourism. Significant research gaps remain, including regional bias towards western Indonesia, lack of standardized sampling and polymer identification methods, limited integration of oceanographic modeling, and insufficient long-term and interdisciplinary studies. Future research should integrate oceanographic, ecological, and socio-economic approaches, leverage remote sensing, modeling, and molecular identification technologies, and support policy and management strategies to mitigate pollution. This review provides a comprehensive synthesis to guide future research, monitoring, and sustainable management of microplastic pollution in Indonesia’s marine environment.