Background/Objectives: Seaweeds have recently gained global attention as sustainable and health-promoting food sources. However, seaweed contains iodine, which, while a beneficial micronutrient, poses health risks if consumed excessively. Therefore, ensur-ing iodine safety has emerged as a critical priority. This study aimed to determine the total iodine content in five major edible seaweeds—laver (Porphyra spp.), sea mustard (Undaria pinnatifida), sea tangle (Saccharina japonica), green laver (Enteromorpha spp.), and hijiki (Hizikia fusiforme)—collected from 12 coastal regions of South Korea during 2020–2024. Methods: A total of 348 samples were analyzed using inductively coupled plasma mass spectrometry after microwave-assisted digestion. Results: The iodine content varied widely among the different species, with sea tangle showing the high-est levels (mean 2,432 mg/kg dry weight). A risk assessment was performed based on the estimated daily intake and hazard index (HI) using both the Korean Ministry of Food and Drug Safety (MFDS) and the Joint FAO/WHO Expert Committee on Food Additives (JECFA) reference values. The HI values were below 1.0 under the MFDS standards, indicating low risk. However, sea tangle showed values exceeding 1.0 under the JECFA standards. Conclusions: These findings highlight the need for species-specific iodine intake guidelines and safety regulations to ensure consumer protection and facilitate global seaweed trade. The study provides a scientific basis for balancing the nutritional benefits of seaweed with the potential risks of overconsumption, assist-ing in the development of national dietary guidelines and providing evidence-based data for navigating international regulatory landscapes.