Kōchi is the main city of the prefecture with over 40% of its population. As of May 31, 2008, the city had an estimated population of 341,860 and a density of 1,110 persons per km². The total area is 309.22 km².
A symbol of the city is its most famous dish, katsuo tataki, made by lightly searing and seasoning tuna.
The area of Kōchi has three distinct geographic sections. The major settled part of the city lies at the head of Urado Bay, in a narrow alluvial plain crossed by several rivers, notably the Kagami River and Kokubu River. The plain is bounded by mountains to the north and a range of hills to the south and west.
The northern mountains form the least densely populated part of the city, with the only settlement being along narrow river valleys. The highest point in Kōchi is Kuishi-yama at 1176 m.
To the south of the city centre, Urado Bay cuts through the hills to its outlet into the Pacific Ocean. The land surrounding the bay and a small strip of the coastline form the third part of the city. This area, although hillier and lense dense than the plain, is nevertheless a major location of housing and port-related industry.
The river plain now containing the city centre was originally settled as a castle town around the seat of the lords of Tosa Province, Kōchi Castle. The castle site was chosen by Lord Yamauchi Katsutoyo in 1601. The city takes its name from that of the castle. As the centre of administration for the province, and the prefecture which succeeded it, the town rapidly grew to become the largest settlement of the region.
During the time of the Meiji Restoration, Kōchi became famous as a centre of pro-imperial ideology, and later for incubating democratic and human rights movements.
The city was incorporated on April 1, 1889.
Tram service began in the city on May 2, 1904, and the city was connected to the national rail network on November 12, 1951.
On April 1, 1998, the city was designated as the first core city on Shikoku.
The mountain holds a public park with views of the city, and is home to stop 31 on the Shikoku Pilgrimage, , as well as the Makino Botanical Garden.
At the mouth of Urado Bay, the remnants of Urado Castle (an earlier provincial seat) stand above , a famous beach with an aquarium and statue of the Kōchi hero Sakamoto Ryoma.
The city also has an extensive bus network.
Kōchi is located on the JR Shikoku's Dosan Line connecting it to northern Shikoku, and via interchanges with the Tosa Kuroshio Railway to the eastern and western parts of Kōchi Prefecture. JR's central station in Kōchi is Kōchi Station.
Kōchi is also serviced by the Kōchi interchange of the Kōchi Expressway which connects to the national expressway system.
Kōchi Ryōma Airport in nearby Nankoku serves Kōchi.