Mariaan de Swardt (born 18 March 1971) is a former tennis player from South Africa, who played as a professional from 1988 to 2001.
She twice represented her native country at the Summer Olympics, in 1992 and 1996, and was a member of the South Africa Fed Cup team in 1992 and 1994–1997.
In 2006, De Swardt became a U.S.
citizen.De Swardt won two Grand Slam titles in mixed-doubles competition, the 1999 Australian Open and the 2000 French Open with partner David Adams.
She also holds four women's doubles titles and reached as high as world No.
11 in WTA women's doubles rankings.
She has one WTA Tour singles title from 1998 and reached a career-high singles ranking of world No.
28 in 1996.
Since retiring from tennis, she has been a commentator for Eurosport and South African television, and she has coached at professional, collegiate and recreational level with her base being at Atlanta, Georgia.
She now resides in Houston, Texas, and is a teaching professional at the River Oaks Country Club.
In 2004, she set up a non-profit charity, the Pet Care Fund, to help animals.