Okayama Prefecture is located in the Chūgoku region on the northern side of the Seto Inland Sea. It covers about 7,114 km², making it the 17th largest prefecture in Japan by area.
Okayama is bordered by Hyōgo Prefecture to the east, Tottori Prefecture to the north, Hiroshima Prefecture to the west, and faces Kagawa Prefecture across the Seto Inland Sea to the south.
The capital is Okayama City, with a population of around 700,000 it is known for Okayama Castle and the historic Korakuen Garden (one of Japan’s three great landscape gardens). Other major cities include Kurashiki, Tsuyama, and Sōja.
The flag of Okayama was adopted on 22nd November 1967. It features a dark purple field with a gold stylized Kanji character ‘岡’ of Oka of Okayama in a circular formation.
| Capital City | Area | 2025 Population |
| Okayama City | 7,114.50 km2 (2,746.92 sq mi) | 1,815,165 |
Japanese prefectural flag designs are used for educational purposes under fair use. Sources include public domain and freely licensed content.