Tōkai-ji, Buddhist temple in Kita-Shinagawa, Japan

Tōkai-ji is a Rinzai Zen temple of the Daitoku-ji branch in Kita-Shinagawa, founded in 1639 by Tokugawa Iemitsu for the monk Takuan Sōhō. The present grounds correspond to the former subtemple Genjō-in (formerly Rinshō-in), a fraction of the original 47,666-tsubo precinct. Its bell dates from 1693, and the temple keeps a portrait of Takuan designated a Tokyo Metropolitan Cultural Property.

Tōkai-ji was founded in 1639 by Shōgun Tokugawa Iemitsu, who had it built in Shinagawa especially for the Zen master Takuan Sōhō so that he could consult him at any time. Takuan had been banished to Kaminoyama in Dewa Province after the 1627 Purple Robe Incident, then pardoned and received by Iemitsu, who rescinded the decree in 1641. In 1694 a fire from Shinagawa-juku burned the temple; Keishō-in, mother of Shōgun Tsunayoshi, sponsored its reconstruction, and the temple bell dates from this rebuilding.

The temple's name comes from Takuan Sōhō's title, Tōkai Kokushi. A portrait of Takuan, a Tokyo-designated cultural property, is kept at the temple, and his grave lies in the Tōkai-ji Ōyama cemetery west of the grounds, a National Historic Site. The cemetery also holds the grave of Kamo no Mabuchi, a kokugaku scholar, likewise a National Historic Site.

The temple stands at 3-11-9 Kita-Shinagawa, Shinagawa, Tokyo, a five-minute walk from Shimbamba Station on the Keikyū Main Line. The main grounds and the Ōyama cemetery are now separate: the cemetery lies at 4-11-8 Kita-Shinagawa, in the former temple precincts, and is reached on foot from the temple.

Takuan Sōhō, the monk for whom Tokugawa Iemitsu built Tōkai-ji in 1639, is also credited with inventing takuanzuke, the yellow pickled daikon named after him. Before his death in 1645 he wrote the character 夢 ("dream") and left a will asking for no tombstone and an unmarked grave, but his disciples erected gravestones at Tōkai-ji and at Sōkyō-ji in Izushi; the Tōkai-ji grave became a National Historic Site in 1926.