Niihama is a city located in the eastern part of Ehime Prefecture, Japan. As of 31 July 2022, the city had an estimated population of 115,824 in 57781 households and a population density of 490 persons per km². The total area of the city is 234.50 square kilometres (90.54 sq mi). It has the third largest population in Ehime, behind the prefectural capital of Matsuyama and the recently expanded city of Imabari. It is famous for its Besshi copper mine as well as the annual Niihama Taiko Festival that is the center of annual drunken and boisterous activity and draws tourists from around the country.

Ehime Prefecture is a prefecture of Japan located on the island of Shikoku. Ehime Prefecture has a population of 1,334,841 and has a geographic area of 5,676 km2. Ehime Prefecture borders Kagawa Prefecture to the northeast, Tokushima Prefecture to the east, and Kōchi Prefecture to the southeast.