Hiroshima Prefecture is a prefecture of Japan located in the Chūgoku region of Honshu. Hiroshima Prefecture has a population of 2,811,410 and has a geographic area of 8,479 km². Hiroshima Prefecture borders Okayama Prefecture to the east, Tottori Prefecture to the northeast, Shimane Prefecture to the north, and Yamaguchi Prefecture to the southwest.

The Chūgoku region , also known as the San'in-San'yō region, is the westernmost region of Honshū, the largest island of Japan. It consists of the prefectures of Hiroshima, Okayama, Shimane, Tottori and Yamaguchi. In 2010, it had a population of 7,563,428.