Background Ferritin reference values vary by age, sex, and ethnicity. We aimed to determine reference values of serum ferritin (SF) and the percentage of transferrin saturation (TSAT) for Korean adolescents. Methods We analyzed data from 2,487 subjects (1,311 male and 1,176 female) aged 10 to 20 from the Korea National Health and Nutrition Examination Survey (2010–2012). Results We calculated age- and gender-stratified means and percentile values for SF and the TSAT of Korean aged 10-20years old. Methods We first plotted mean SF and TSAT for each gender according to age. In male, the mean serum ferritin tends to be relatively constant during 10 to 14 year-olds and trend upward thereafter. In female, the mean serum ferritin trend downward until the age of 15 years and constant thereafter. Thus, significant sex difference of ferritin exists from 14 years. High level of SF was associated with obesity, and lower level of SF was associated with anemia and menarche state. Conclusion We established reference values of serum ferritin and percentage of transferrin saturation according to age and sex. The reference values for SF calculated in this study can be used to test the association between its value and other defined disease in Korean children and adolescents.