The order Mysida Haworth, 1825 consists of four families. Of these, only family Mysidae Dana, 1850 has been reported in Korea. Two opossum shrimps, Nipponomysis calcarata Takahashi and Murano, 1986 and Exacanthomysis japonica Murano, 1991 belonging to the tribe Mysini of Mysidae, are reported for the first time from Korean waters. The present study is the second report of these two species in the world. The illustrations and descriptions of these species are provided herein. As a result of this study, 47 species of opossum shrimps including N. calcarata and E. japonica are now recorded on the mysids in Korean fauna.