Omitama is a city located in Ibaraki Prefecture, Japan. As of 1 July 2020, the city had an estimated population of 48,776 in 18,311 households and a population density of 337 persons per km2. The percentage of the population aged over 65 was 30.0%. The total area of the city is 144.74 square kilometres (55.88 sq mi).

Ibaraki Prefecture is a prefecture of Japan located in the Kantō region of Honshu. Ibaraki Prefecture has a population of 2,828,086 and has a geographic area of 6,097.19 square kilometres. Ibaraki Prefecture borders Fukushima Prefecture to the north, Tochigi Prefecture to the northwest, Saitama Prefecture to the southwest, Chiba Prefecture to the south, and the Pacific Ocean to the east.