This paper provides a revised synonymic list for the 13 species belonging to 11 genera of Cicadidae (Hemiptera) from the Korean Peninsula: Platypleura kaempferi (Fabricius, 1794), Suisha coreana (Matsumura, 1927), Lyristes intermedius (Mori, 1931), Cryptotympana atrata (Fabricius, 1775), Graptopsaltria nigrofuscata (De Motschulsky, 1866), Oncotympana fuscata Distant, 1905, Leptosemia takanonis Matsumura, 1917, Meimuna mongolica (Distant, 1881), Meimuna opalifera (Walker, 1850), Cicadetta abscondita Lee, new species, Kosemia admirabilis (Kato, 1927), Kosemia yezoensis (Matsumura, 1898), and Tettigetta isshikii (Kato, 1926). Major changes from preceding lists are: Lyristes japonicus (Kato, 1925) is deleted from the list of Korean Cicadidae considered as having been erroneously recorded due to mislabeling; Euterpnosia inanulata Kishida, 1929 syn. nov. is synonymized with Leptosemia takanonis; the Korean species previously identified as Cicadetta montana (Scopoli, 1772) is described as a new species, Cicadetta abscondita Lee, new species; Cicadetta admirabilis (Kato, 1927) and Cicadetta yezoensis (Matsumura, 1898) are transferred to Kosemia Matsumura, 1927 stat. rev., which is resurrected from junior synonymy with Cicadetta Amyot, 1847, to become Kosemia admirabilis, new combination and Kosemia yezoensis, new combination; Leptopsalta Kato, 1928 syn. nov. is synonymized with Kosemia; Cicadetta isshikii (Kato, 1926) is transferred to Tettigetta Kolenati, 1857 to become Tettigetta isshikii, new combination; the Korean species previously treated as Cicadetta pellosoma (Uhler, 1861) is re-identified as Tettigetta isshikii. The lectotype of Cicada pellosoma is designated. A key to the subfamilies, tribes, subtribes, genera, and species of the Korean Cicadidae is provided. Diagnostic characters for the three genera of Cicadettini in Korea are provided. Information is also provided on the adult activity periods and distributions for the 13 Korean cicadid species.