<p>Polycyclic aromatic hydrocarbons pose inconsistent yet increasing threats to freshwater reservoirs worldwide, with implications for ecosystem health and water security. Although local-scale contamination has been widely documented, a comprehensive global synthesis of polycyclic aromatic hydrocarbon occurrence and drivers in reservoirs remains lacking. Here we developed a framework of data compilation, arrangement and statistics to integrate existing data to determine the geographical distribution and potential sources of polycyclic aromatic hydrocarbon pollution in reservoirs globally. Statistical analyses revealed spatial heterogeneity in dominant components and pollution levels across continents. Almost 38% of water samples exceeded an ecologically relevant threshold (0.20 μg l⁻¹), and 42% of sediment samples surpassed the threshold effect concentration, indicating widespread ecological risks. Cluster analysis and source apportionment of the reservoir-level data identified three distinct polycyclic aromatic hydrocarbon patterns, each shaped by region-specific land-use practices, combustion sources and climatic factors. These findings emphasize and inform the need for region-specific monitoring and management strategies, such as expanding monitoring in subtropical and temperate regions, with a focus on polycyclic aromatic hydrocarbon accumulation in aquatic organisms.</p>