Adachi is a special ward located in Tokyo Metropolis, Japan. It is located north of the heart of Tokyo. The ward consists of two separate areas: a small strip of land between the Sumida River and Arakawa River and a larger area north of the Arakawa River. The ward is bordered by the cities of Kawaguchi, Sōka and Yashio in Saitama and Katsushika, Sumida, Arakawa, and Kita in Tokyo. The ward is called Adachi City in English.
As of May 1, 2015, the ward has an estimated population of 692,707, and a population density of 13,010 persons per km². The total area is 53.25 km².
The Adachi Land Transportation Office is located here, and automobiles registered at this office bear Adachi number plates.