丸之內（丸の内，Marunouchi）是日本東京都千代田區皇居外苑與東京車站之間 一帶的地區，行政區劃分為1丁目至3丁目。丸之內是日本有名的商業街，同時也是三菱集 團的大本營。
Chiyoda (千代田区, Chiyoda-ku?) is one of the 23 special wards in central Tokyo, Japan. In English, it calls itself Chiyoda City. As of October 2007, the ward has an estimated population of 45,543 and a density of 3,912 persons per km², making it by far the least populated of the special wards. The total area is 11.64 km², of which the Imperial Palace takes up 12 percent.
Chiyoda consists of the Palace and a surrounding radius of about 1 kilometer. It inherited the name, literally meaning "field of a thousand generations," from Chiyoda Castle (the other name of Edo Castle). Many government institutions, such as the Diet, Prime Minister's residence, and Supreme Court, are located in Chiyoda, as are Tokyo landmarks such as Yasukuni Shrine, Tokyo Station, and the Budokan. Fifteen embassies are located in Chiyoda.