- Other Names: 硫黄島 (iou shima / iou jima), トカラ硫黄島 (Tokara iou shima)
- Japanese: 硫黄鳥島 (Iou Torishima)
Iô Torishima is an island in the Amami Islands group, located to the west of Tokunoshima, and southwest of Amami Ôshima. Though most nearly neighboring islands which are administered as part of Kagoshima prefecture, Iô Torishima is administered as part of the city of Kumejima, Okinawa prefecture.
A major source of sulfur for the Ryûkyû Kingdom, the island's name literally means "sulfur bird island." It is also known simply as Iôjima ("sulfur island"), and as Tokara Iôjima, to distinguish it from the island of the same name famous for the Battle of Iwo Jima.
Though the rest of the Amamis were absorbed by the Shimazu clan following their 1609 invasion of Ryûkyû, Iô Torishima was allowed to remain the territory of the Ryûkyû Kingdom, and remains part of Okinawa prefecture (not Kagoshima) today.
- Richard Pearson, Ancient Ryukyu, University of Hawaii Press (2013), 8.