Ōbaku (from Chinese 黃檗; pinyin "huang bo") is one of the three main Japanese Zen Buddhist school, along with the Rinzai and Soto sects.. It was founded in 1654 when the Chinese monk Yinyuan Longqi and his disciple Muyan, followers of the Linji tradition, went to Japan. The head temple Mampukuji was founded at Uji in 1661. In 1664 Muyan replaced Yinyuan Longqi as chief priest there. In 1671 he established a second temple, Zuishōji at Shirokane, Edo. Chinese monks remained master of the temple for the first thirteen generations, until the Japanese monk Ryūtō became the fourteenth.

Ōbaku monks were famed for their skill at calligraphy, and three of them, Ingen Ryuki, Mokuan Shoto and Sokuhi Nyoitsu were known as the "Three Brushes of Ōbaku".