Ryukyu Islands (rēōō´kyōō), Jap. Ryukyu-retto or Nansei-shoto [southwest group], archipelago (1990 est. pop. 1,500,000), c.1,850 sq mi (4,790 sq km), SW Japan, in the W Pacific Ocean. The chain stretches about 650 mi (1,050 km) between Taiwan and Japan, separating the East China Sea from the Philippine Sea. The Ryukyus are composed of three principal groups: they are, from north to south, the Amami Islands (part of Kagoshima prefecture), the Okinawa Islands, and the Sakishima Islands (both part of Okinawa prefecture). Okinawa is the largest and most important island of the Ryukyus.
The islands are the exposed tops of submarine mountains and are of volcanic or coral origin; there are several active volcanoes in the group. Although the islands are low, with few points above 2,000 ft (610 m), they have rugged hills and little flatland. The Ryukyus have a subtropical climate with much rain and are often hit by typhoons. The chief agricultural products are sugarcane, sweet potatoes, pineapples, and rice. Fishing is also important to the economy. Some light industry is found in Naha, Okinawa, the Ryukyus' largest city. Sugar and canned pineapples account for most of the exports. The inhabitants speak a language said to be related to that of the Ainu.
The islands were the site of an ancient independent kingdom that had its capital at Shuri, on Okinawa. The Chinese reached the islands in the 7th cent. but did not exact tribute until the 14th cent. In the 17th cent. the Japanese prince of Satsuma invaded the islands, which thereafter paid tribute to both Japan and China. Commodore Matthew Perry of the U.S. navy landed in the Ryukyus in 1853. The entire archipelago was incorporated into the Japanese empire in 1879, but the islands were generally neglected by Japan.
During World War II the Ryukyus were the scene of fierce fighting between U.S. and Japanese forces, with the United States winning control of the islands in 1945. After the war the islands south of lat. 30°N were placed (Aug., 1945) under a U.S. military governor at Naha. The Ryukyus became a key salient of the U.S. Pacific defense perimeter, and major military bases were established on Okinawa. In 1951, at the San Francisco Peace Conference, the Japanese were given residual sovereignty over the islands, but the United States retained actual control.
The Amami group was returned to Japan in 1953, and the Japanese desire to regain the remaining U.S.-held islands was a source of friction between the two countries for nearly two decades. In 1962 the occupation administration was liberalized, and in 1968, after a series of negotiations, the United States permitted the popular election of the governor of the Ryukyus and the seating of Ryukyu representatives in the Japanese Diet. The archipelago was returned to Japan in May, 1972. The United States was allowed to retain its military bases subject to certain limitations.
Other forms of the name are Lu-chu, Loo-choo, Liu-kiu, and Riukiu.