Suwa is a city located in Nagano Prefecture, Japan. As of 1 March 2019, the city had an estimated population of 48,972 in 20698 households, and a population density of 452 persons per km². The total area of the city is 109.17 square kilometres (42.15 sq mi).

Nagano Prefecture is a landlocked prefecture of Japan located in the Chūbu region of Honshū. Nagano Prefecture has a population of 2,007,682 and has a geographic area of 13,561.56 square kilometres (5,236.15 sq mi). Nagano Prefecture borders Niigata Prefecture to the north, Gunma Prefecture to the northeast, Saitama Prefecture to the east, Yamanashi Prefecture to the southeast, Shizuoka Prefecture and Aichi Prefecture to the south, and Gifu Prefecture and Toyama Prefecture to the west.