As long-lived filter-feeders, baleen whales integrate and reflect changes in ocean contamination, including exposure to microplastics (MPs). This study reports the occurrence of MPs in multiple tissues of North Atlantic fin whales (Balaenoptera physalus) collected off southwestern Iceland in 2023. Five tissues (blubber, muscle, liver, lung, and kidney) from eight individuals were analyzed using the Micro-FTIR and Micro-Raman spectroscopy under strict contamination control. MPs occurred in 32.5%