Margaritha Constantia "Mariette" Van Heerden (born 22 November 1952) is a Zimbabwean former discus thrower and shot puter. Van Heerden was born in Southern Rhodesia but grew up in South Africa and was the holder of South African records in shot put and discus throw as well as a multiple South African champion in both these events (1980 and 1981). She was awarded Springbok colours during the years of the international sports boycott of South Africa. Van Heerden moved back to South Africa after 1987 and is the mother of South African swimmer Katheryn Meaklim.