Shimoda is a city and port located in Shizuoka Prefecture, Japan. As of 1 February 2024, the city had an estimated population of 19,670 in 10,436 households, and a population density of 188 persons per square kilometre. The total area of the city is 104.71 square kilometres (40.43 sq mi). In the 1850s, Japan was in political crisis over its increasing inability to maintain its national seclusion policy and the issue of what relations, if any, it should have with foreign powers. For a few years, Shimoda was central to this debate.