Robert Anthony John "Bob" Hewitt (born 12 January 1940) is a former professional tennis player from Australia. In 1967, after marrying a South African, he became a South African citizen.Hewitt's most significant accomplishment was winning all Grand Slam doubles titles, both in men's and mixed doubles (US Open, Wimbledon, Australian Open, French Open) and being central to South Africa's only Davis Cup title in 1974.