This study presents the first evidence of microplastics in natural sea turtle nests at Chagar Hutang Turtle Sanctuary (CHTS) on Redang Island, a crucial habitat for green turtles. Microplastics were detected in all studied turtle nests (0-70 cm depth), with a total abundance of 12,270 microplastic items per kg dry weight of sand. Fibers (80.7 %) were the most prevalent shape, primarily black (37.9 %), with a high proportion of small-sized particles (<300-1000 μm), indicating prolonged accumulation and environmental degradation. These microplastics, primarily polyethylene terephthalate (PET) and polyethylene (PE), are likely from fishing nets, food packaging, and textiles. Despite the sanctuary's remote location, it is heavily impacted by microplastics carried by tides and wind, raising concerns about their potential effects on turtle egg incubation. The findings offer critical insights into the impact of microplastics on turtle habitats and underscore the urgent need for conservation efforts to protect green sea turtles in Malaysia.