Tsu (津市) is a city located in Mie Province and was granted city status on April 1, 1889. With a total area of 711.19 km² and a population of 276.773 inhabitants, including about 5.714 foreign citizens.

In January 2006, Hisai City and the Age and Ichishi districts were merged into Tsu City, making it the prefecture’s largest by area and second largest by population behind Yokkaichi.

Temperatures in Tsu are highest in August reaching 31.2°C, and the lowest in January reaching a low of 1.9°C.