Kanagawa Prefecture (神奈川県, Kanagawa-ken^?) is a prefecture located in the southern Kantō region of Japan. The capital is Yokohama. Kanagawa is part of the Greater Tokyo Area.

The prefecture has some archaeological sites going back to the Jōmon period (around 400 BC). About 3,000 years ago, Mount Hakone produced a volcanic explosion which resulted in Lake Ashi on the western area of the prefecture.

It is believed^{[by whom?]} that the Yamato Dynasty ruled this area from 5th century onwards. In the ancient era, its plains were very sparsely inhabited.

Kamakura in central Sagami was the capital of Japan during the Kamakura period (1185–1333).

In medieval Japan, Kanagawa was part of the provinces of Sagami and Musashi.

During the Edo period, the western part of Sagami Province was governed by the daimyo of Odawara Castle, while the eastern part was directly governed by the Tokugawa Shogunate in Edo (Tokyo).

Commodore Matthew Perry landed in Kanagawa in 1853 and 1854 and signed the Convention of Kanagawa to force open Japanese ports to the United States. Yokohama, the largest deep-water port in Tokyo Bay, was opened to foreign traders in 1859 after several more years of foreign pressure, and eventually developed into the largest trading port in Japan. Nearby Yokosuka, closer to the mouth of Tokyo Bay, developed as a naval port and now serves as headquarters for the U.S. 7th Fleet and the fleet operations of the Japan Maritime Self-Defense Force. After the Meiji Period, many foreigners lived in Yokohama City, and visited Hakone. The Meiji Government developed the first railways in Japan, from Shinbashi (in Tokyo) to Yokohama in 1872.