Zhang Daoling (Chang Tao-ling), aka Zhang Ling. Eastern Han dynasty (2nd Century C.E.) Taoist hermit who founded the Zhengyi Mengwei Tianshi Dao ("Tradition of the Celestial Master of the Mighty Commonwealth of Orthodox Oneness") sect of Taoism, also known as the "Tianshi Dao" ("Way of the Celestial Masters") sect or the "Wudou Mi Dao" ("Way of Five Bushels of Rice") sect.

According to tradition, in 142 C.E., Lao Zi (Lao Tse) himself appeared to Zhang Daoling, and informed the hermit that the world was coming to an end, to be followed by an era of Great Peace. Lao Zi explained that those following him would go on to another life, part of the "Orthodox One Covenant with the Powers" ("Zhengyi meng wei").

Zhang Daoling went on to found the first regular Daoist church/community as noted above. A major change instituted by the new Covenant was the rejection of food and animal sacrifices. Also, the teachings of Lao Zi as transmitted by Zhang Daoling included the first true Taoist religious pantheon as distinguished from the prior ancient religion of China.

It is said that Zhang Daoling did not die; he ascended to heaven with his wife Yong and two disciples. One of the Immortals, he is now known as the "Ancestral Celestial Master" or "Celestial Master Zhang."