Wú Wù 吳悞 was a Southern-Sòng Daoist alchemist, author of KR5c0298 Dān fáng xū zhī 丹房須知 (“What Must Be Known about the Elixir Chamber”) — a practical manual on alchemical laboratory procedure, equipment, and ingredients, dated by its 1163 preface. The Dān fáng xū zhī is one of the most important technical alchemical texts from the Southern Sòng, extensively illustrated in the received Zhèng tǒng Dào zàng edition.