Introduction: Obesity is one of the risk factors for various metabolic diseases that will cause various kinds of complications. Continuous sub-acute chronic inflammation is characterized by increased inflammatory markers, one of which is ferritin. Low iron that can be detected with ferritin, may alter thyroid metabolism. Chronic inflammatory conditions can cause disruption of thyroid hormone production. The purpose of this study was to examine the correlation between ferritin levels and thyroid hormone levels in obese populations. Methods: This was a cross-sectional study enroling 41 subjects with obesity with BMI >27 in Diponegoro National Hospital Semarang. Thyroid hormone levels (TSH, T3, FT3, T4 and FT4) and ferritin were examined with an immunology analyzer. Spearman correlation test was performed. p<0.05 was considered as statistically significant. Results: There were significant weak positive correlations between ferritin levels with T3 (r=0.38; p=0.02) and with FT3 levels (r=0.33; p=0.05). There were no correlations between ferritin levels with TSH, T4, and FT4. Conclusion: Ferritin levels might have association with T3 and FT3 levels in obese population. If confirmed by further studies, ferritin and thyroid hormones levels could be used in therapeutic monitoring in obese population.