William Knox D'Arcy (October 11, 1849 – May 1, 1917) is a British businessman who is one of the principal founders of the oil and petrochemical industry in Persia (Iran).
The D’Arcy Concession is signed in 1901 and allows D'Arcy to explore, obtain, and market oil, natural gas, asphalt, and ozokerite in Persia.