Millon Reacdia (French Millet Richard; December 5, 1794, Denicourt - October 8, 1885) was a French chemist.
Reaction was a member of the Paris Academy of Medicine (1833) and the French Academy of Medicine and Surgery (1840). He represented France at the French National Institute of Metrology in 1845. He was nominated as a foreign member of the Royal Society for the Improvement of Industry (19 April 1856) and naturalized in Great Britain in 1932.
Richard's varied interests led to his election as a member of the French Philosophical Society on May 16, 1821. In 1873, the French Academy appointed him to the biology department.