Iki, island, north-central Nagasaki ken (prefecture), western Kyushu, Japan. It lies in the Eastern Channel, about 10 miles (16 km) off the coast of Kyushu, and occupies 52 square miles (134 square km). Most of its area is tableland; cereals, oranges, and tobacco are the important crops. The fishing industry yields mackerel and cuttlefish. Anchorages are at Gōnoura (the chief town), Katsumoto, and Ashibe. The island served as a gateway for Chinese and Korean culture to enter Japan.