Kōtō (江東区, Kōtō-ku) is a special ward in the Tokyo Metropolis in Japan. It is known as Kōtō City in English. As of May 1, 2025, the ward has an estimated population of 543,730, and a population density of 12,648/km (32,760/sq mi). The total area is 42.99 km (16.60 sq mi).
Kōtō is east of the Tokyo metropolitan center, bounded by the Sumida River to the west and the Arakawa River to the east. Its major districts include Kameido, Kiba, Kiyosumi, Monzen-nakachō, Shirakawa, and Toyosu. The waterfront area of Ariake is in Kōtō, as is part of Odaiba, Ojima.