EFSA assessed the relevance of seaweed and halophyte consumption to the dietary exposure to heavy metals (arsenic, cadmium, lead and mercury) and the iodine intake in the European population. Based on sampling years 2011-2021, there were 2,093 analytical data available on cadmium, 1,988 on lead, 1,934 on total arsenic, 920 on inorganic arsenic (iAs), 1,499 on total mercury and 1,002 on iodine. A total of 697 eating occasions on halophytes, seaweeds and seaweed-related products were identified in the EFSA Comprehensive European Food Consumption Database (468 subjects, 19 European countries). From seaweed consumption, exposure estimates for cadmium in adult 'consumers only' are within the range of previous exposure estimates considering the whole diet, while for iAs and lead the exposure estimates represent between 10% and 30% of previous exposures from the whole diet for the adult population. Seaweeds were also identified as important sources of total arsenic that mainly refers, with some exceptions, to organic arsenic. As regards iodine, from seaweed consumption, mean intakes above 20 μg/kg body weight per day were identified among 'consumers only' of Kombu and Laver algae. The impact of a future increase in seaweed consumption ('per capita') on the dietary exposure to heavy metals and on iodine intake will strongly depend on the seaweeds consumed. The exposure estimates of heavy metals and iodine intakes in 'consumers only' of seaweeds were similar to those estimated in a replacement scenario with selected seaweed-based foods in the whole population. These results underline the relevance of the current consumption of seaweeds in the overall exposure to different heavy metals and in the intake of iodine. Recommendations are provided for further work needed on different areas to better understand the relationship between seaweed consumption and exposure to heavy metals and iodine intake.