This study assessed the distribution of microplastics (MPs) in the gills, intestines, and muscles of the common carp (Cyprinus carpio), one of main fish species consumed by humans living in the lower regions of the Han River in South Korea. In total, 891 MP particles were detected in 15 carps, with an average of 59.4 ± 45.5 particles/specimen, indicating severe MP contamination. The predominant MP form was fragment (86%), and the size range was 0.02–0.10 mm. Thirty MP particles were detected in the muscle samples (n = 10), primarily in sizes < 0.1 mm (89%). The most common types of polymers detected in this study were polyethylene (≥42%), polystyrene (≥20%), and polypropylene (≥19%), which were at the same level as the polymer ratio of domestic plastic production/use. No correlation was observed between the length of common carp and the number of MPs detected in different body tissues, indicating an abundance of MPs in the environment rather than by residue and accumulation. These findings contribute to the evaluation of the potential impact of edible fish on human health and emphasize the need to develop strategies to reduce MP contamination originating from various potential land sources.