Tsu is a city located in Mie Prefecture, Japan. As of 31 July 2021, the city had an estimated population of 274,879 in 127,273 households and a population density of 390 persons per km². The total area of the city is 711.11 square kilometres. Although the second largest city in the prefecture in terms of population, the prefectural capital and a large concentration of national government offices and educational facilities, make the city the administrative and educational center of Mie Prefecture.