Li Tieguai; also known as Tieguai Li and born as Li Yuan; is a Chinese mythological character and one of the Eight Immortals. Though he is often portrayed as being ill-tempered and irascible; he is benevolent and kind to the poor; sick and the needy; curing and alleviating the pain of others with special medicine from his magical gourd. Li Tieguai was said to have been born in the Yuan Dynasty.

In Chinese folklore; Li Tieguai was said to have originally been Laozi's apprentice; which would have put his birth some time in the sixth century BCE rather than during the Yuan Dynasty. Either way; he is said to have devoted himself to religious contemplation for 40 years; overcoming various tests and tasks Laozi set for him eventually becoming an immortal.

Li Tieguai was said to have been a handsome man once; but during his path towards immortality; there was an incident when his spirit left his body and ascended to Heaven to meet other immortals. While away; his body was cremated; and when Li's spirit returned; he had to enter the corpse of an ugly and disheveled homeless beggar who had just recently starved to death. Li Tieguai is the second most popular of the Eight Immortals; and associated with medicine.