Soto (曹洞 宗; jap.: sōtō-shū) is (or was)one of the five sects of Zen-Buddhism in China.

In Japan, it is one of the famous Zen-sects, as well as the Rinzai- and Obaku-sect. With 14,700 temples and nearly 7 million adherents (in 1989) it is the biggest of these Zen-sects.

Soto, still practised both in Japan and in the West, stresses shikantaza, the meditation in simply sitting in a fixed posture. Sitting is not seen as the means to an end, but as an end in itself, a direct means of expressing enlightenment and Buddhahood in an instant.

The sect was founded by Dogen Zenji (1200-1253) a leading religious figure in Japan, whose thoughts are the basis of the sect.