The Ōsumi and Tokara Islands, the northernmost of the islands, fall under the cultural sphere of the Kyushu region of Japan; the people are ethnically Japanese and speak a variation of the Kagoshima dialect of Japanese. The Amami, Okinawa, Miyako, and Yaeyama Islands have a native population collectively called the Ryukyuan people, named for the former Ryukyu Kingdom that ruled them. The varied Ryukyuan languages are traditionally spoken on these islands, and the major islands have their own distinct languages. In modern times, the Japanese language is the primary language of the islands, with the Okinawan Japanese dialect prevalently spoken. The outlying Daitō Islands were uninhabited until the Meiji period, when their development was started mainly by people from the Izu Islands south of Tokyo, with the people there speaking the Hachijō language.
The Ryukyu islands are commonly divided into two or three primary groups:
either administratively, with the Northern Ryukyus being the islands in Kagoshima Prefecture (known in Japanese as the "Satsunan Islands") and the Southern Ryukyus being the islands in Okinawa Prefecture (known in Japanese as the "Ryukyu Islands"),
or geologically, with the islands north of the Tokara Strait (Ōsumi and Tokara) being the Northern Ryukyus, those between the Tokara Strait and Kerama Gap (Amami and Okinawa) being the Central Ryukyus, and those south of the Kerama Gap (Miyako and Yaeyama) being the Southern Ryukyus.
The following are the grouping and names used by the Hydrographic and Oceanographic Department of the Japan Coast Guard. The islands are listed from north to south where possible.
The Geospatial Information Authority of Japan, another government organization that is responsible for standardization of place names, disagrees with the Japan Coast Guard over some names and their extent, but the two are working on standardization. They agreed on February 15, 2010, to use Amami-guntō (奄美群島) for the Amami Islands; prior to that, Amami-shotō (奄美諸島) had also been used.