Nishiizu is a town located in Kamo District, Shizuoka Prefecture, Japan. As of 1 August 2019, the town had an estimated population of 7,798 in 3764 households, and a population density of 74 persons per km². The total area of the town was 105.52 square kilometres (40.74 sq mi).

Shizuoka Prefecture is a prefecture of Japan located in the Chūbu region of Honshu. As of September 2023, Shizuoka Prefecture has a population of 3,555,818 and has a geographic area of 7,777.42 km2 (3,002.88 sq mi). Shizuoka Prefecture borders Kanagawa Prefecture to the east, Yamanashi Prefecture to the northeast, Nagano Prefecture to the north, and Aichi Prefecture to the west.