Ryōgoku Kokugikan (両国国技館, Ryōgoku Kokugi-kan?), also known as Ryougoku Sumo Hall, is an indoor sporting arena located in the Yokoami neighborhood (bordering to the Ryōgoku neighborhood) of Sumida, one of the 23 wards of Tokyo in Japan, next to the Edo-Tokyo Museum. It is the third building built in Tokyo associated with the name kokugikan. The current building was opened in 1985 and has a capacity of 13,000 people. It is mainly used for sumo wrestling tournaments (honbasho) and hosts the hatsu (new year) basho in January, the natsu (summer) basho in May, and the aki (autumn) basho in September. It also houses a museum about sumo. The venue is also used for other indoor events, such as boxing, pro wrestling, and music concerts. In past years, it has hosted the finals of the G1 Climax, an annual tournament held by New Japan Pro Wrestling.
In 1659, the Ryōgoku Bridge was built, spanning the Sumida River just upstream of its confluence with the Kanda River. Its name, meaning "two provinces," came from its joining Edo (the forerunner of Tokyo in Musashi Province) and Shimōsa Province. The neighborhood derived its name from that of the bridge.
The Forty-seven Ronin avenged the death of their lord, Asano Naganori, by breaking into the mansion of his enemy, Kira Yoshinaka, in 1703. Part of the mansion has been preserved in a public park in Ryōgoku.
Ryōgoku Station opened in 1904, bringing rail transportation to the area.
It is regarded as the heartland of professional sumo. Most training stables or heya are based there. The first Ryōgoku Kokugikan stadium for sumo was completed in 1909. The present one was built in 1985 in the Yokoami neighborhood north of Ryōgoku. Three of professional sumo's six annual official tournaments take place there.