Yokkaichi (四日市市 Yokkaichi-shi, literally "fourth day market") is a city located in Mie Prefecture, West Japan. As of August 2015, the city had an estimated population of 204,174 and a population density of 2,561.46 people per square mile (988.98 persons/km²). The total area was 79.71 square miles (206.45 km2).
Yokkaichi is located in north-central of Mie Prefecture, which is northeastern Kii Peninsula. It stretches the width of Mie Prefecture, and is bordered by Ise Bay on the Pacific Ocean to the east, and Shiga Prefecture to the northwest.
Yokkaichi has a humid subtropical climate (Köppen climate classification Cfa) with hot summers and cool winters. Precipitation is significant throughout the year, but is much lower in winter.
Yokkaichi is a manufacturing center that produces Banko ware (a kind of porcelain), automobiles, cotton textiles, chemicals, tea, cement, and computer parts such as flash memory by Toshiba subsidiary Yokkaichi Toshiba Electronics.