A newly recorded species of gammaridean amphipod, Cryptodius kelleri (Br$ddot{u}$ggen, 1907) belonging to the family Odiidae Coleman and Barnard, 1991 collected from the east coastal area of Korea. Cryptodius kelleri (Br$ddot{u}$ggen) is characterized by the medially expanded maxillipedal palp article 2, smooth dorsal pereonites, propodochelate gnathopod 1, subchelate gnathopod 2, lacking the posterior process on the basis of pereopods 5-7, dorsal carination of pleonite 3, posterolateral upturned process of pleonite 3, and an entire telson. The species is described and fully illustrated in the present study. A key is also provided to the species of genus Cryptodius. This is the first record of the family Odiidae from Korea.