The area of present-day Oga was part of ancient Dewa Province, dominated by the Satake clan during the Edo period, who ruled Kubota Domain under the Tokugawa shogunate.

The city of Oga was created on March 31, 1954, by the merger of the town of Funagawaminato with the four neighboring villages of Wakimoto, Iriai, Ogatanaka and Toga.

[citation needed] Oga has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 18 members.

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

East Japan Railway Company – Oga Line Oga is famous for its Namahage Festival, a traditional event held on New Year's Eve in which groups of men dressed as ogre-like deities called "Namahage" with masks and straw raincoats visit houses at night.