Whaddon Niewoudt (born 6 January 1970) is a South African middle-distance runner. He competed in the men's 3000 metres steeplechase at the 1992 Summer Olympics. Later in his career, Niewoudt participated in road events as well; he was part of the South African team at the 2000 Chiba Ekiden marathon relay, helping the team finish in 2nd place.