Martina Hingis (born 30 September 1980 in Ko?ice, Slovakia, then Czechoslovakia) is a retired Swiss professional tennis player who spent a total of 209 weeks as World No. 1. She won five Grand Slam (Grand Slam (tennis)) singles titles (three Australian Opens, one Wimbledon (Wimbledon Championships), and one US Open (US Open (tennis))). She also won nine Grand Slam womens doubles titles, winning a calendar year doubles Grand Slam in 1998, and one Grand Slam mixed doubles title.

Hingis set a series of "youngest-ever" records before ligament injuries in both ankles forced her to withdraw temporarily from professional tennis in 2002 at the age of 22. After several surgeries and long recuperations, Hingis returned to the WTA (Womens Tennis Association) tour in 2006. She then climbed to world number 6 and won three singles titles. On 1 November 2007, Hingis announced her retirement from tennis while admitting she had tested positive (Doping (sport)) for cocaine during Wimbledon in 2007. She denied using the drug. On 4 January 2008, she was banned from tennis for two years after both cocaine tests (samples A and B) turned positive. She has stated that she will not return to professional tennis when this ban expires. She participated in the seventh (2009) series of the BBCs Strictly Come Dancing, partnering Matthew Cutler, where she was the first contestant to be voted out. In 2010 she will be reunited with her former doubles-partner, Anna Kournikova in the womens senior doubles at Wimbledon.