<p>Contamination of seafood with microplastics (MPs) poses a threat to food safety and public health, particularly in coastal regions where dried fish is a dietary staple. This study assessed MP contamination in fresh and sun-dried fish collected from processing centers along the Gulf of Mannar, southeast India, and evaluated potential post-harvest contamination sources, including curing salt, rinse water, processing-area soil, and airborne fallout. MPs were detected in all samples. Dried fish muscle contained significantly higher MP loads (7.25 ± 1.36 items g⁻¹) than fresh fish (3.67 ± 1.04 items g⁻¹), indicating substantial contamination during processing. Spearman correlation and principal component analysis revealed strong associations between MP levels in dried fish and curing salt (<i>ρ</i> = 0.99), airborne fallout (<i>ρ</i> = 0.97), and processing-area soil (<i>ρ</i> = 1.00), with these factors jointly explaining over 85% of the total variance. PERMANOVA further confirmed that processing centers accounted for 48% of the variance in MP loads in dried fish, compared with only 12% attributable to species identity. Source apportionment analysis indicated proportional contributions from curing salt (38%), airborne fallout (27%), and processing-area soil (20%). Fibers dominated MP morphology (62% in dried fish), while polymer and color profiles suggested inputs from ambient air, packaging materials, plastic trays, and salt. Based on FAO/WHO seafood consumption models, estimated adult exposure was 170,820 MPs year⁻¹, with dried fish contributing 44% (75,400 MPs year⁻¹) despite lower consumption frequency. These findings highlight the need for improved hygiene in traditional fish processing to reduce dietary MP exposure.</p>