Huangbo', Japanese: Ōbaku Kiun) (died 850[a]) was an influential master of Zen Buddhism during the Tang dynasty.

Very little about Huángbò's life is known for certain as, unlike other Transmission of the Lamp literature, there is no biographical information included with Huángbò's collection of sayings and sermons, the Chuanxin Fayao (傳心法要, "Essentials of Mind Transmission") and the Wanling Lu (宛陵錄, "Record of Wan-ling"; Japanese: Enryōroku).

[b] Huángbò began his monastic life on Mount Huangbo in Fujian province, receiving the Buddhist name Xiyun (Hsi-yun).

Tiantai and sought teachings from the National Teacher Nanyang Huizhong (Wade–Giles: Nan-yang Hui-chung; Japanese: Nan’yō Echū).

At some point he may also have studied under Nanquan Puyuan (748–835) (Wade–Giles: Nan-ch’üan P’u-yüan; Japanese: Nansen Fugan), a student of Mazu Daoyi (Wade–Giles: Ma-tsu Tao-i; Japanese: Baso Dōitsu) (709–788)[1] However, Huángbò's main teacher was Baizhang Huaihai (Wade–Giles: Pai-chang Huai-hai; Japanese: Hyakujo Ekai), another Mazu student, and it was from Baizhang that Huángbò received Dharma transmission.

He was given the posthumous title (probably under the urging of Pei Xiu who became chief minister of the central government in 853) of “Chan Master Without Limits” (Tuan Chi Ch’an Shih).

John Blofeld says he died on Mount Huangbo during the T'ai Chung reign of the Tang dynasty, or between 847 and 859.

Blofeld says his memorial pagoda is "The Tower of Spacious Karma" and that it was Emperor Hsüan Tsung who gave him the title "The Zen Master Who Destroys All Limitations".

[d] Pei compiled the teachings from his own notes and sent the manuscript to the senior monks on Mount Huangbo for further editing and emendation.

The “official” version of the Huángbò literature was published as part of the Transmission of the Lamp, Compiled during the Ching-te Period, in 1004.

Huángbò's teaching centered on the concept of “mind” (Chinese: 心 xin), a central issue for Buddhism since its inception.

[10]Huangbo connected the One Mind with the single spiritual brilliance (or one pure radiance) of the Śūraṅgama Sūtra, which divides to become the six sense spheres.

"[14] For Huangbo, when one transcends the dharmas of being and non-being, one's mind is like the sun whose brilliance shines naturally, and this requires no effort.

Huángbò's teaching on this reflected the Indian concept of the tathāgatagarbha, the idea that within all beings is the nature of the Buddha.

This is because the form bodies merely respond to circumstances and phenomena, giving teachings in accordance with the differing capabilities of sentient beings, in various appearances and guises.