Mark Foster, English swimmer
Mark Andrew Foster (born 12 May 1970) is an English former competitive swimmer who represented Great Britain in the Olympics and world championships, and swam for England in the Commonwealth Games. Foster is a former world champion and won multiple medals in international competition during his long career. He competed primarily in butterfly and freestyle at 50 metres.

Foster is a specialist short-course (25 metre pool) swimmer. In terms of medals and longevity (1986–2008), he is amongst the most successful British swimmers of all time. He was the fastest swimmer in the country by age 15. He made a comeback at the national championships in July 2007 winning both events he competed in after barely training. He achieved the fifth best time in 2007 in the world at 50 metres freestyle and retired for the second time after the 2008 Olympics. He has six World Championship titles, two Commonwealth titles and eleven European titles to his name.