Sir Jan Petrus du Plessis (born 22 January 1954) is a British businessman of Afrikaner descent. He was the non-executive chairman of BT Group, and the former non-executive chairman of Rio Tinto Group plc, and a former non-executive director of the Lloyds TSB Group. Du Plessis was placed tenth in The Times 2006 Power 100, a list which rates the most powerful people in British business.