Susaki is located in central Kōchi Prefecture, facing Tosa Bay of the Pacific Ocean to the south and bordered by mountains to the north.

During the Edo period, the area was part of the holdings of Tosa Domain ruled by the Yamauchi clan from their seat at Kōchi Castle.

Following the Meiji restoration, the town of Susaki was established within Takaoka District, Kōchi with the creation of the modern municipalities system on October 1, 1889.

Susaki 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 Kōchi 1st district of the lower house of the Diet of Japan.

Shikoku Railway Company - Dosan Line Susaki's official mascot is Shinjo-kun, a Japanese river otter wearing a hot pot ramen dish for a hat.