Zelyony (Russian: Остров Зелёный, romanized: Ostrov Zelyony, Russian pronunciation: [ˈostrəf zʲɪˈlʲɵnɨj]; Japanese: 志発島, romanized: Shibotsu-tō, Japanese pronunciation: [ɕi̥botsɯ̥toː]) is an unpopulated and uninhabited island in the Kuril Island chain, Sakhalin Oblast, Russia.

Although it is administered by Russia and had been previously by the Soviet Union, it has been claimed by Japan since 1945.

At the end of World War II, the Japanese military garrison surrendered to Soviet troops, the island was incorporated into the Soviet Union, and the Japanese population was repatriated to Japan.

Zelyony was the site of an incident between the United States and the Soviet Union in April 1983.

As part of the US-South Korean joint military exercise Team Spirit, six U.S. navy Corsair II attack aircraft flew over the island.