Leachate produced from municipal solid waste landfill serves as a potential pathway for microplastics (MPs) release into the environment with a high potential for soil, surface water, and groundwater contamination. These MPs not only persist for longer duration of time in the landfill but also interact with toxic chemical contaminants. These interactions arise from the hydrophobic characteristics and minuscule size of MPs, which absorb a variety of emerging toxic contaminants present in these systems thereby amplifying the risk to surrounding environment. This study was performed to investigate the abundance, characteristics, and pollution risk of MPs in leachate from two contrasting landfill systems in the cities of Chandannagar and Baidyabati, India. A total of 8 leachate samples from an uncontrolled landfill (UCL), i.e., open dump, and 24 samples from different leachate treatment units (LTUs) of a controlled landfill (CL) were evaluated. Particle sizes of 1-5 mm (41.9%) in UCL and 0.025-0.5 mm (46.2%) in CL were predominant. Seven different types of polymers were identified in untreated leachate samples from UCL having concentration 53.4 ± 6.69 p/L (mean ± standard deviation) and in CL 34.7 ± 4.73 p/L. The predominant shapes were films, fragments, and fibers in UCL, whereas fragments and fibers dominated in CL. Polyethylene and polypropylene were the most frequent types of polymers observed in both sites. In CL, collection well, aeration lagoon, and sedimentation pond were used for LTUs, in which overall 83.3% MPs removal was achieved. High removal in LTUs highlights the importance of engineered systems for leachate management. However, optimization of these units is needed for enhanced removal of particles <
0.5 mm. For UCL the findings suggest urgent need for implementing basic containment and treatment systems, particularly given their higher pollution risk indices. Varying landfill designs, waste compositions, and weather conditions of specific locations restrict generalisation of the findings to other regions. Therefore, long-term monitoring studies across different geographical and climatic conditions are recommended to develop more comprehensive management strategies.