Jeju Island, due to its position at the southern tip of the Korean Peninsula in Northeast Asia, is a on the unique enclave of the many southern elements in the area and features a mixture of subtropical, temperate, boreal, and arctomontane taxa. Among the arctomontane species recorded in this study wasAnthelia juratzkana; among the temperate species wasDactyloradula brunnea, and subtropical species wereCavicularia densa,Pallavicinia subciliata,Wiesnerella denudata, andMegaceros flagellaris. A valuable species as first recorded for the Jeju Island isCryptocoleopsis imbricata. The distribution patterns of these species suggest that the flora of Jeju Island is a meeting place between boreal and subtropical floras. We recorded 222 taxa belonging to 45 families, 80 genera, 209 species, 9 subspecies, and 4 varieties. Among these, 86 species are reported as new to the flora of Jeju Island. A checklist based on a study of 1697 specimens is also provided.