Eight species of Hippoboscidae from 13 bird hosts are reported from the Republic of Korea (ROK). A new species of the genus Crataerina von Olfers with reduced wings is described, and it was collected from a Pacific Swift (Apus pacificus Latham; Apodiformes, Apodidae). Icostafenestella Maa is recorded for the first time from the ROK. Ornithoica tridens Maa is synonymized with O. momiyamai Kishida. Turdus chrysolaus Temminck and Zoothera ( = Turdus) sibirica (Pallas) are recorded as new birds host for I. fenestella and O. unicolor Speiser, respectively. Morphological identification keys are also presented for the species of the genus Crataerina in the Palaearctic region, and for the species of the Hippoboscidae in the ROK.