Scincella vandenburghi is a small lygosomine skink, distributed in Tsushima Island and the Korean Peninsula as well as their adjacent islands. We analyzed the within-species genetic variation among the populations of Tsushima Island, Cheju Island, and the Korean Peninsula using partial sequences of mitochondrial DNA, cytochrome b and cytochrome c oxidase subunit I genes. We detected 20 haplotypes in total. Little genetic divergence was observed among the populations of S. vandenburghi from the Korean Peninsula, Tsushima Island, and Cheju Island. Genetic diversity was low in this species and demographic statistics suggested the recent expansion of distribution. Considering that Tsushima Island has been separated from the Korean Peninsula since 0.43 million years ago and that a narrow seaway had persisted between these two areas even during the Last Glacial Maximum, the low genetic divergence in S. vandenburghi suggests that this species expanded its range from the Korean Peninsula to Tsushima Island by oversea dispersal.