Orthohantaviruses are negative-sense, single-stranded RNA viruses harbored by rodents, shrews, moles, and bats. Of the shrew-borne orthohantaviruses in the Republic of Korea (ROK), Jeju orthohantavirus (Jeju virus, JJUV) was found on Jeju Island. This small-scale epidemiologic survey investigated the geographic distribution and molecular phylogeny of JJUV in the ROK. In 32 trapping sites, tissues of 84 Crocidura shantungensis were analyzed for JJUV RNA. JJUV RNA was detected in seven (8.3%) shrews captured on the Korean peninsula. The molecular epidemiologic survey demonstrated the prevalence of JJUV by geographic distribution. The RNA loads of JJUV were evaluated in various tissues. Entire coding sequences of tripartite genomes were recovered from two JJUV strains on the mainland. Phylogenetic relationships of the JJUV revealed a distinct geographic lineage of mainland strains from the strains on Jeju Island. This study sheds light on the molecular epidemiology, phylogeographic diversity, and virus-host co-divergence of JJUV, ROK.