Rationale: Strontium from rocks accumulates in human tissues through the food chain. In permanent teeth, the strontium isotope ratio reflects childhood geology, which is useful for tracing geographical origins. This study constructs a strontium isotope ratio map from tooth enamel and assesses its correlation with a rock isotope map. Methods: To develop South Korea’s first strontium isotope map, we collected tooth enamel samples from a dental clinic and analyzed their strontium isotope ratios. The Geographic Information System interpolation method was applied to model spatial variations, and multivariate discriminant analysis was used to identify key elemental markers. Results: The analysis revealed that the average strontium isotope of tooth enamel was high in the granite areas of the northwestern region, while the average was low in the volcanic areas of the southeastern region. In addition, multivariate discriminant analysis of tooth elemental data revealed that Cr, Ti, Mn, and Fe were the key elements that clearly distinguished Jeju, a volcanic island, from inland regions. Conclusions: Despite the influence of a globalized supermarket diet, strontium isotopes and trace elements in teeth fairly reflected lithological effects. This study provides critical data to support forensic investigations by aiding in the geographical identification of unidentified skeletons or missing persons.