Liu Yiming (1734–1821) was a Chinese ophthalmologist, philosopher, and writer. He was one of the main representatives of Taoist Internal Alchemy, or Neidan. He was an 11th-generation master of one of the northern branches of the Longmen 龍門 (Dragon Gate) lineage, and the author of a large number of works that illustrate his views on both Taoism and Neidan.