Kamaishi (釜石市, Kamaishi-shi) is a city located on the Sanriku rias coast in Iwate Prefecture, Japan.

[1] The total area of the city is 441.43 square kilometres (170.44 sq mi)[2] Kamaishi is located in the Kitakami Mountains of south-central Iwate Prefecture, with the Pacific Ocean to the east.

Iwate Prefecture Kamaishi has a humid subtropical climate (Köppen Cfa) characterized by mild summers and cold winters.

The area was inhabited by the Emishi people, and came under the control of the imperial dynasty during the early Heian period.

In the 1850s, the feudal domains of Japan were engaged in an arms race to develop the first Western-style armaments, particularly large guns.

The Nanbu Domain constructed blast furnaces of a foreign design in Kamaishi under the direction of military engineer Takatō Ōshima.

The first of these furnaces was lit on December 1, 1857; a day honored as the start of modern iron production in Japan.

The German director imported two large steam-driven blast furnaces of the latest design from Britain and set up a railway with 15 miles of track and a locomotive purchased from Manchester to deliver the ore. Production began in 1880 but had to be stopped soon after due to a lack of charcoal.

The earthquake measured magnitude 8.5 while the tsunami on the Iwate coast reached as high as 24 meters in places – the highest ever recorded in Japan at the time.

On 14 July 1945, under the command of Rear Admiral John F. Shafroth Jr., the battleships USS South Dakota, Indiana, Massachusetts, and Alabama, the heavy cruisers Chicago and Quincy, and nine destroyers bombarded the Japan Ironworks and warehouses, along with nearby oil tanks and vessels, to great effect.

[14] The subsequent decision to rebuild the breakwater at a cost of over $650 million was criticised as "a waste of money that aims to protect an area of rapidly declining population with technology that is a proven failure".

Kamaishi has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 19 members.

In terms of national politics, the city is part of Iwate 2nd district of the lower house of the Diet of Japan.

The city also has a semi-professional association football club, Nippon Steel Corp. Kamaishi S.C., which plays in the 5th division Tohoku Soccer League.