Oleniy Island (also spelt as Oleny and Oleni) (Russian: Остров Олений) is a single island in the Kara Sea just a few kilometers offshore, north of the coast of one of the arms of the Gydan Peninsula in North Siberia. It is covered with tundra and swamps and it is 53 km in length and its average width is 27 km, having an area of 1197 km².