Omitama is located in central Ibaraki Prefecture, in the low-lying flatlands north of Lake Kasumigaura.

Ibaraki Prefecture Omitama has a Humid continental climate (Köppen Cfa) characterized by warm summers and cool winters with light snowfall.

Omitama has a mayor-council form of government with a directly elected mayor and a unicameral city council of 20 members.

In terms of national politics, the city is part of Ibaraki 2nd district of the lower house of the Diet of Japan.

Agriculture is the mainstay of the local economy, with cash crops including chives, strawberries, melons, rice and lotus roots.