Kōtō (江東区, Kōtō-ku^?) is one of the 23 special wards of Tokyo, Japan. As of 2008, the ward has an estimated population of 442,271 and a population density of 11,070 persons per km². The total area is 39.48 km². The ward refers to itself as Kōtō City in English.

Kōtō is located east of the Tokyo metropolitan center, bounded by the Sumida-gawa to the west and the Arakawa River to the east. Its major districts include Kameido, Kiba, Kiyosumi, Monzen-nakachō, Shirakawa, and Toyosu. The newly developed waterfront area of Ariake is in Kōtō, as is part of Odaiba.