, often called , was a province of Japan. It was at the extreme western end of Honshà «, in the area that is today Yamaguchi Prefecture. Nagato bordered on Iwami and Suà  Provinces.
Although the ancient capital of the province was Shimonoseki, Hagi was the seat of the Chà Âshà « han (fief or domain) during the Edo period. Nagato was ruled by the Mà Âri clan before and after the Battle of Sekigahara.
In 1871 with the abolition of feudal domains and the establishment of prefectures (Haihan Chiken) after the Meiji Restoration, the provinces of Nagato and Suà  were combined to eventually establish Yamaguchi Prefecture. At the same time, the province continued to exist for some purposes. For example, Nagato is explicitly recognized in treaties in 1894 (a) between Japan and the United States and (b) between Japan and the United Kingdom.
Historically, the oligarchy that came into power after the Meiji Restoration of 1868 had a strong representation from the Chà Âshà « province, as Ità  Hirobumi, Yamagata Aritomo, and Kido Kà Âin were from there. Other natives famous for their role in the restoration include Yoshida Shà Âin, Takasugi Shinsaku, and Kusaka Genzui among others.
The Japanese battleship Nagato was named after this province.
Sumiyoshi jinja was the chief Shinto shrine (ichinomiya) of Nagato.