Plastic is one of the fastest growing materials and production is on course to double, to more than one billion tons a year, by 2050. With that, will come more pollution. Every year, 5.6 million to 25.4 million tons plastic waste is estimated to enter the global ocean. The Asia-Pacific region has been identified as the world’s largest contributor of mismanaged plastic waste (MPW). Rivers play a crucial role in transporting land-derived material (for example, ~91% of the global MPW) and freshwater to the coastal ocean, the latter creating convergent river plume fronts. Convergent frontal systems trapping suspended materials and planktonic organisms have been well documented. Whether and how plume fronts are important to the distribution, transport, and fate of plastic debris (including microplastic smaller than 5 mm) is largely unknown. Knowledge on this topic could provide insights into prioritizing riverine plastic mitigation strategies. Our study uses a combination of measurements and numerical models to determine how plastics are impacted by plume fronts. Four observational campaigns were conducted at plume fronts of the Yellow River and Terengganu River to examine plastic densities from the water and zooplankton samples in and around plume frontal zones to test the hypothesis that plastics accumulate at plume fronts, leading to a high ingestion risk in zooplankton. Plastic debris impacted by the dynamics of the Yellow River plume front were studied by performing high-resolution observations of hydrographic and biogeochemical variables. Finally, numerical simulations were carried out to predict the transport of plastics in frontal systems.