The Korean species of Illiberis Walker are revised. A total of 10 species are recognized, including four species new to Korea: I. rotundata Jordan, I. psychina (Oberthur), I. consimilis Leech, and I. hyalina (Staudinger). The identities of I. cybele Leech and I. assimilis Jordan, the two ambiguously defined Korean species, are reconfirmed with the examination of type specimens and additional materials. Photos of the adults and type materials are provided, and male and female genitalia of each species are illustrated. Biology and distribution for each species are briefly discussed with the larval host records from Korea.