Plastic pollution poses serious ecological risks to marine organisms through various pathways, yet a comprehensive risk assessment is lacking. Here we assess the global risks of plastic ingestion, entanglement, pollutant adsorption (methylmercury, MeHg; perfluorooctane sulfonate, PFOS) and additive leaching (bisphenol A; phthalate esters) by integrating a marine plastic model and multisize marine organism data, as well as MeHg and PFOS datasets. Our analysis reveals that ingestion risks vary with the body size of organisms, and are influenced by both biomass distribution and plastic concentration patterns. Entanglement hotspots align with regions of flourishing coastal fisheries, highlighting a substantial threat to marine species. Ingestion risks and toxicity from leached additives are concentrated in the mid-latitude North Pacific Ocean, mid-latitude Atlantic Ocean and northern Indian Ocean. Plastics exhibit high adsorption of PFOS in the North Atlantic and East and Southeast Asian coasts (0.1-0.3 pg m) and of MeHg in the northern Indian and southwestern Atlantic oceans (1-18 pg m). Using future emission scenarios, we project plastic concentrations and estimate reduced risks under emission control strategies. These findings emphasize the urgent need for targeted mitigation efforts and policy interventions to curb escalating impacts of plastic pollution on marine ecosystems.