After the Meiji restoration, the town of Ōkawa was established on May 1, 1889 with the creation of the modern municipalities system.

It annexed the neighboring villages of Kawaguchi, Onojima, Taguchi, Mimata, and Kimuro on April 1, 1955 and was raised to city status.

Ōkawa has a mayor-council form of government with a directly elected mayor and a unicameral city council of 15 members.

In terms of national politics, the city is part of the Fukuoka 6th district of the lower house of the Diet of Japan.

Ōkawa is noted for its high concentration of furniture-related woodworking manufacturers, which began in the late Muromachi period.