Chūō (中央区, Chūō-ku^?) is one of the 23 special wards that form the heart of Tokyo, Japan. The ward refers to itself as Chūō City in English.

Its Japanese name literally means "Central Ward," and it is historically the main commercial center of Tokyo, although Shinjuku has risen to challenge it since the end of World War II. The most famous district in Chūō is Ginza (銀座), built on the site of a former silver mint from which it takes its name. The gold mint, or Kinza (金座), formerly occupied the site of the present-day Bank of Japan (日本銀行) headquarters building, also in Chūō.

As of 2008, the ward has an estimated resident population of 108,943 and a density of 9654 persons per km². However, because of the concentration of businesses, offices and retail space, the daytime population swells to an estimated 650,000.

Chūō is in the central area of Tokyo, surrounded by the five special wards of Chiyoda, Minato, Taitō, Sumida, and Kōtō.

Administratively, Chūō is divided into the three zones of Nihonbashi, Kyobashi and Tsukishima. Nihonbashi and Kyobashi are predominantly commercial areas on the east side of Tokyo Station, and incorporate the famous districts of Ginza and Tsukiji. Tsukishima is a separate island in Tokyo Bay dominated by condominium towers.

Tokyo (東京, Tōkyō^?, "Eastern Capital") [toːkʲoː], English /ˈtoʊki.oʊ/; officially Tokyo Metropolis (東京都, Tōkyō-to^?), is one of the 47 prefectures of Japan. Tokyo is the capital of Japan, the center of the Greater Tokyo Area, and the largest metropolitan area of the world. It is the seat of the Japanese government and the Imperial Palace, and the home of the Japanese Imperial Family. Tokyo is in the Kantō region on the southeastern side of the main island Honshu and includes the Izu Islands and Ogasawara Islands. Tokyo Metropolis was formed in 1943 from the merger of the former Tokyo Prefecture (東京府, Tōkyō-fu^?) and the city of Tokyo (東京市, Tōkyō-shi^?).

The Tokyo Metropolitan government administers the 23 special wards of Tokyo (each governed as a city), which cover the area that was the city of Tokyo, as well as 39 municipalities in the western part of the prefecture and the two outlying island chains. The population of the special wards is over 8 million people, with the total population of the prefecture exceeding 13 million. The prefecture is part of the world's most populous metropolitan area with upwards of 35 million people and the world's largest urban agglomeration economy with a GDP of US$1.479 trillion at purchasing power parity in 2008, ahead of New York City metropolitan area, which ranks second on the list. The city hosts 47 of the Fortune Global 500 companies, the highest amount of any city.