Purpose This observational study examined the relationship between self-reported dietary patterns-omnivore, pescatarian, vegetarian, and vegan-and iron status among Swedish teenage girls. Additionally, we compared the consumption of various food groups in relation to iron status. Methods Data were collected from 475 female high school students in Malm & ouml; and Lund, Sweden, using questionnaires on dietary habits, iron supplementation, and demographic factors. Participants were classified into dietary groups: 347 omnivores, 38 pescatarians, 27 non-consumers of red meat, 60 vegetarians and 3 vegans. Blood samples were analysed for ferritin and haemoglobin levels to determine iron status. Iron deficiency was defined as ferritin < 15 <mu>g/L, and anaemia as haemoglobin < 110 g/L if < 19 years and < 117 g/L if >= 19 years. ANOVA and logistic regression were used to compare biomarker levels and the prevalence of iron deficiency and anaemia across dietary groups. Results Omnivores had the highest estimated ferritin levels (19.6 <mu>g/L), which was significantly higher than pescatarians (14.7 mu g/L, p = 0.03), and vegans/vegetarians (10.9 mu g/L, p < 0.001). Overall 38.1% of participants were iron deficient. Vegetarians/vegans and pescatarians were significantly more likely to be iron deficient (69.4%, p < 0.001 and 49.4%, p-value 0.016, respectively) compared to omnivores (30.5%). Lower red meat consumption and higher intake of vegetarian patties and legumes were linked to an increased risk of iron deficiency. Anaemia prevalence (haemoglobin < 110 g/L if < 19 years and < 117 g/L if >= 19 years) was 3% across all dietary groups. Conclusion This study highlights a higher prevalence of iron deficiency among Swedish teenage girls adhering to plant-based diets. Public health strategies should promote balanced diets that ensure adequate iron intake and absorption while considering environmental sustainability. Regular screening and targeted dietary recommendations are essential for supporting the health of this population.