Josiah Marshall Heath (died 1851) was an English metallurgist, businessman and ornithologist, who invented the use of manganese to deoxidise steel. In India he learned the local steelmaking processes, including wootz, but having failed to found a profitable steel mill there he returned to England and settled in Sheffield. His patent kick-started Sheffield's steel industry, but the poor wording of his patent caused competitors not to pay him royalties, and he died in poverty.