Tsukubamirai is a city located in Ibaraki Prefecture, Japan. As of 1 October 2020, the city had an estimated population of 51,035 in 20,030 households and a population density of 645 persons per km2. The percentage of the population aged over 65 was 26.3%. The total area of the city is 79.16 square kilometres (30.56 sq mi).