Awaji Island is an island in Hyōgo Prefecture, Japan, in the eastern part of the Seto Inland Sea between the islands of Honshū and Shikoku. The island has an area of 592.17 square kilometres. It is the largest island of the Seto Inland Sea.

Hyōgo Prefecture is a prefecture of Japan located in the Kansai region of Honshu. Hyōgo Prefecture has a population of 5,469,762 and a geographic area of 8,400 square kilometres. Hyōgo Prefecture borders Kyoto Prefecture to the east, Osaka Prefecture to the southeast, and Okayama and Tottori prefectures to the west.