Marine plastic debris has become a major concern on the northern coast of Jaffna, Sri Lanka, where it poses a threat to marine resources. A preliminary study was conducted to investigate the abundance and characteristics of marine plastic debris at four major fish landing sites in the northern coast of Jaffna, using the Clean Coast Index (CCI) and Plastic Abundance Index (PAI). The results revealed that the average abundance of marine debris and plastic debris were 1.71 ± 0.42 items/m2 and 1.66 ± 0.57 items/m2, respectively. The most common types of plastic debris were plastic rope and net pieces (23.2%), followed by unidentified weathered plastic fragments (16.7%), beverage bottles (16.2%), bottle caps and lids (13%), and styrofoam (14.1%). The recognized sources of plastic debris were mainly fishing-based activities, recreation activities, transboundary sources, and unidentified sources. The cleanliness level of the fish landing sites were categorized as extremely dirty, with high levels of plastic debris, resulting in a CCI above 10 and a PAI value over 8. This study realized the consequence of implementation of a proper plastic waste management framework in the northern coast of Jaffna and highlights the necessity to address buoyant debris on the northern Indian Ocean.