After the start of the Meiji period, Gamagōri Village in Hoi District, Aichi Prefecture was proclaimed on October 1, 1889.

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

In terms of national politics, the city is part of Aichi District 14 of the lower house of the Diet of Japan.

Companies headquartered in the city include: As part of Mikawa Wan Quasi-National Park with numerous scenic offshore islands, Gamagōri is noted for marine sports.

The small fishing community of Nishiura is noted for its onsen (hot spring resorts), some of which are located near its beach front.

The area is famous for the medicinal properties of its water and a number of hotels have sprung up to accommodate the tourists visiting these spas.