Elwood Haynes (October 14, 1857 – April 13, 1925) was an American inventor, metallurgist, automotive pioneer, entrepreneur and industrialist. He invented the metal alloy stellite and independently co-discovered martensitic stainless steel along with Englishman Harry Brearley in 1912 and designed one of the earliest automobiles made in the United States. He is recognized for having created the earliest American design that was feasible for mass production and, with the Apperson brothers, he formed the first company in the United States to produce automobiles profitably. He made many advances in the automotive industry.