Plastic pollution has emerged as one of the most persistent and pervasive environmental threats to coastal ecosystems worldwide, with significant implications for the socioeconomic well-being of coastal communities. Coastal environments, including beaches, estuaries, mangroves, coral reefs, and fishing grounds, act as major sinks for mismanaged plastic waste. As plastics accumulate, they alter ecosystem structure and function, degrade critical habitats, and introduce microplastics into marine food webs. These ecological disruptions directly undermine the socioeconomic stability of coastal populations whose livelihoods rely on fisheries, aquaculture, tourism, and ecosystem-based services. Tourism-dependent households suffer from reduced visitor inflow, loss of employment, and declining local business revenue as beaches and waterfronts become polluted. The public health costs associated with contaminated seafood, compromised drinking water, and increased disease burden further deepen socioeconomic vulnerability. These multidimensional impacts disproportionately affect low-income and marginalized coastal groups, especially small-scale fishers, women engaged in fish processing, and informal waste pickers. Plastic pollution not only undermines livelihoods but also aggravates poverty traps, intensifies social inequality, and limits progress toward sustainable development goals. This chapter synthesizes current scientific evidence on how plastic pollution translates into measurable socioeconomic impacts, identifies high-risk livelihood groups, and highlights emerging challenges in coastal governance. It also evaluates policy gaps and management strategies, emphasizing the need for circular economy approaches, community-based interventions, improved waste governance, and integrated coastal zone management. Understanding the multidimensional consequences of plastic pollution is essential for designing effective mitigation frameworks that safeguard coastal livelihoods and enhance the resilience of marine socioecological systems.