Alfred Beit (1853-16 July 1906) was a South African diamond magnate.
Born in Hamburg, he emigrated to Cape Colony in 1875 during the "diamond rush" at Kimberley. He became one of a group of financiers who gained control of the diamond-mining claims in the Central, Dutoitspan, and De Beers mines and became life-governor of De Beers and also a director of numerous other companies such as the Rand Mines, Rhodesia Railways and the Beira Railway Company. With Cecil Rhodes he financed the unsuccessful Jameson Raid of late 1895 which was intended to trigger a coup in the Transvaal.