Plastic pollution has become one of the most important environmental problems of the 21st century. Microplastics (MPs)and nanoplastics (NPs) are increasingly found in ecosystems on land, in freshwater, and in the ocean. Wastewater systems sit at the core of the problem, collecting plastics from households, industry, and urban runoff whilesimultaneously serving as both major conduits to aquatic environments and key control points for their removal. This chapter examines wastewater management in plastic pollution from three perspectives. First, it highlights the sources,properties, and fate of plastics in wastewater. Second, it examines the limitations of current wastewater treatmenttechniques. Finally, it evaluates conventional and advanced treatment strategies for plastic mitigation. Special attention ispaid to hybrid systems that integrate several procedures to overcome current constraints. By integrating fundamentalknowledge with innovative technologies, this chapter advances sustainable wastewater management in the age of plastics,in line with the United Nations Sustainable Development Goals (SDGs) 6 (Clean Water and Sanitation), 12 (ResponsibleConsumption and Production), and 14 (Life Below Water).