The 65^th Medical Brigade and Medical Department Activity-Korea, in collaboration with the Migratory Birds Research Center, National Park Research Institute, conducted a migratory bird tick-borne disease surveillance program during 2014–2015 on two small, remote, uninhabited islands, Hong (Gull) Island, southern Gyeongnam Province, and Nan Island, western Chungnam Province, Republic of Korea (ROK). Argasid ticks were collected from Black-tailed Gull (Larus crassirostris) nestlings that had recently died and associated nest soil/litter, and all tick life history stages were identified morphologically. Because morphological keys are unreliable for the identification of adult and nymphal argasid ticks, identifications were confirmed by genotyping using polymerase chain reaction techniques. A total of 29 Ornithodoros capensis larvae and 2 Ornithodoros sawaii larvae were collected from 4 of 7 (57.1%) Black-tailed Gull nestlings that had recently died. An additional five O. capensis (2 males, 1 nymph, and 2 larvae) were collected from nest soil/litter. Only O. sawaii larvae (2/41, 4.9%) were collected from dead Black-tailed Gull nestlings on Nan Island. This is the first report of O. capensis from these seabird breeding islands.