A new species belonging to the genus Cyclopinoides Lindberg, 1953 (Cyclopinidae) is described from three beaches in Korea and Japan, as the first record of the genus from the Pacific. Among five species currently recognized in the genus, the new species resembles C. schulzi Herbst, 1964 from the Red Sea in sharing the character combination of 20-segmented antennule and stumpy caudal rami. However, C. orientalis n. sp. differs from it by relatively longer caudal rami (2.5-2.8 times as long as wide in female and about 1.6-1.8 times in male, while less than 2 times in female and about 1.3 times in male of C. schulzi), and by the transformation of an outer distal spine to a slender seta on the distal exopodal segment of leg 4. Moreover, C. orientalis n. sp. is discernible from C. schulzi in having a pyriform copulatory tube (against elongated tubular style in C. schulzi). A key to the species hitherto known in the genus is provided.