The Oriental odd-tooth snake (Lycodon orientalis), sometimes called the Japanese odd-tooth snake, is a species endemic to Japan, belonging to the family Colubridae. It is found in Hokkaido, Honshu, Shikoku, Kyushu, the Goto Islands, Iki Island, Izu Ōshima, the Oki Islands, Sado Island, Tanegashima, and Yakushima. It has also been reported in Shiashkotan, one of the Kuril Islands. The snake was first described in 1880 by both Hilgendorf and Günther However according to Stejneger the description by Hilgendorf was published before that of Günther.