Edo Castle (江戸城 -jō) was built in 1457 by Ota Dokan in what is now the Chiyoda ward of Tokyo, but was then known as Edo. Tokugawa Ieyasu established the Tokugawa shogunate here, and as the residence of the shogun and location of the bakufu, it functioned as the military capital during the Edo period of Japanese history. Kokyo, the Imperial Palace, stands on the site today. Some moats, walls and ramparts survive. However, during the Edo period, the grounds were much more extensive, with Tokyo Station and the Marunouchi section of the city lying within the outermost moat. It also encompassed Kita-no-maru Park, the Nippon Budokan Hall and other landmarks of the area.

At times, Edo Castle had a donjon in the style typical of castles of Japan. However, earthquakes and fires took their toll, and throughout most of the Edo period (and since), it had no such structure. Despite this, jidaigeki (such as Abarembo Shogun) set in Edo usually depict Edo Castle as having a donjon, and substitute Himeji Castle for that purpose.

On April 21, 1701, in Matsu no Ōrōka (the Great Pine Corridor) of Edo Castle, Asano Takumi-no-kami drew his short sword and attempted to kill Kira Kozuke-no-suke, triggering the events of the Forty-seven Ronin.

Many place names in Tokyo derive from Edo Castle. Otemachi ("the town in front of the great gate"), Takebashi ("the Bamboo Bridge"), Toranomon ("the Tiger Gate"), Uchibori Dōri ("Inner Moat Street"), Sotobori Dōri ("Outer Moat Street"), and Marunouchi ("Within the enclosure") are examples.