Siming (Chinese: 司命; pinyin: Sīmìng) refers to a Chinese deity or deified functionary of that title who makes fine adjustments to human fate, with various English translations (such as, the Master of Fate, Controller of Fate, Deified Judge of Life, Arbiter of Fate, Director of Allotted Life Spans, and Director of Destinies). Siming is both an abstract deity (or title thereof) and a celestial asterism.
Siming, as Director of Destinies, has the bureaucratic function of human lifespan allocation. Siming seems to have roots in the shamanic traditions, then later to have somewhat assimilated with the Kitchen God, as in the Daoist case of the Three Worms, in which Siming becomes a deity to whom home household activities are periodically reported,
As an asterism, or apparent stellar constellation, Siming is associated with the Wenchang Wang star pattern, near the Big Dipper, in what is more or less Aquarius.
Sometimes the term Siming is qualified by 大 (da, meaning "big" or "greater") or by 少 (shao, meaning "small" or "lesser").