Okinawa Island (沖縄本島, Okinawa-hontō^?, alternatively 沖縄島 Okinawa-jima; Okinawan: ウチナー Uchinaa; Nakijin: フチナー Fuchinaa) is the largest of the Okinawa Islands and the Ryukyu (Nansei) Islands of Japan, and is home to Naha, the capital of Okinawa Prefecture. The island has an area of 1,201.03 square kilometers (463.72 sq mi). It is roughly 640 kilometres (400 mi) south of the rest of Japan.

The island of Okinawa was the site of most of the ground warfare in the Battle of Okinawa during World War II, when American Army and Marine Corps troops fought a long and bloody battle to capture Okinawa, so it could next be used as the major air force and troop base for the planned invasion of Japan. During this 82-day-long battle, about 95,000 Imperial Japanese Army troops and 12,510 Americans were killed, and in addition to these deaths, somewhere between 42,000 and 150,000 Okinawan civilians - approximately one quarter of the civilian population - were also killed.

During the American military occupation of Japan (1945–52), which followed the Imperial Japanese surrender on September 2, 1945, in Tokyo Bay, the United States controlled Okinawa Island and the nearby Ryukyu islands and islets. These all remained in American military possession until June 17, 1972, with numerous U.S. Army, U.S. Marine Corps, and U.S. Air Force bases there.