Niigata Prefecture (新潟県, Niigata-ken; Japanese pronunciation: [niː.ɡa.ta, -taꜜ.keɴ, niː.ŋa-]) is a prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,131,009 (1 July 2023) and is the fifth-largest prefecture of Japan by geographic area at 12,584.18 km² (4,858.78 sq mi). Niigata Prefecture borders Toyama Prefecture and Nagano Prefecture to the southwest, Gunma Prefecture to the south, Fukushima Prefecture to the east, and Yamagata Prefecture to the northeast.

Niigata is the capital and largest city of Niigata Prefecture, with other major cities including Nagaoka, Jōetsu, and Sanjō. Niigata Prefecture contains the Niigata Major Metropolitan Area centered on Niigata with a population of 1,395,612, the largest metropolitan area on the Sea of Japan coast and the twelfth-largest in Japan. Niigata Prefecture is part of the historic Hokuriku region and features Sado Island, the sixth largest island of Japan in area following the four main islands and Okinawa Island.

History

Until after the Meiji Restoration, the area that is now Niigata Prefecture was divided into Echigo Province (on the mainland) and Sado Province. During the Sengoku period, the Nagao clan, who were at times vassals to the Uesugi, ruled a fief in the western part of modern Niigata from Kasugayama Castle. The most notable member of the Nagao clan was Nagao Kagetora, later and better known as Uesugi Kenshin. He unified the leaders of Echigo Province and became its sole ruler.