In 2002, the Ministry of the Environment classified some tidal flats of the Ōma shoreline as one of the 500 Important Wetlands in Japan particularly for its biodiversity of marine flora, especially several varieties of kelp.

In 2000, Ōma was the setting for an NHK television series Watashi no Aoi Sora (私の青空) starring Tabata Tomoko.

Ōma has a mayor-council form of government with a directly elected mayor and a unicameral town council of ten members.

Ōma is part of Shimokita District which, together with the city of Mutsu, contributes three members to the Aomori Prefectural Assembly.

In terms of national politics, the city is part of Aomori 1st district of the lower house of the Diet of Japan.

The town was famous for having the "black diamond" of tuna, which are caught in the traditional manner by hand in two-person boats, and sold under the "Ōma" registered brand.