Ōta is a city located in Gunma Prefecture, Japan. As of 31 August 2020, the city had an estimated population of 224,358 in 109,541 households, and a population density of 1300 persons per km2. The total area of the city is 60.97 square kilometres (23.54 sq mi).

Gunma Prefecture is a landlocked prefecture of Japan located in the Kantō region of Honshu. Gunma Prefecture has a population of 1,937,626 and has a geographic area of 6,362 km2. Gunma Prefecture borders Niigata Prefecture and Fukushima Prefecture to the north, Nagano Prefecture to the southwest, Saitama Prefecture to the south, and Tochigi Prefecture to the east.