The 23 special wards (特別区, tokubetsu-ku) of Tokyo are a unique form of municipality under Japan's 1947 Local Autonomy Law. They are city-level wards: primary subdivisions of a prefecture with municipal autonomy. Together, they cover 627 km (242 sq mi) and, as of 2024, house roughly 9.8 million residents, yielding a density of about 15,742 people/km (40,770 people/sq mi). Similar ward systems are legally possible in other prefectures, but none have been established.
Tokyo's 23 special wards unite with 39 ordinary municipalities (cities, towns and villages) to their west to form Tokyo Metropolitan Prefecture. Without the ordinary municipalities the special wards account for what was the core Tokyo City, before this was abolished in 1943 under the Tōjō Cabinet. It was four years later, during the Occupation of Japan, that autonomy was restored to Tokyo City by means of the special wards, each being given a directly elected mayor and assembly like all other cities, towns and villages in Japan.