Martina Hingis (born September 30, 1980 in Košice, Slovakia) is a former World No. 1 professional tennis player. She won five Grand Slam singles titles (three Australian Open, one Wimbledon, and one U.S. Open). She also won nine Grand Slam women's doubles titles, winning a calendar year Grand Slam in 1998, and one Grand Slam mixed doubles title. She spent a total of 209 weeks as World No. 1.

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 tour in 2006. She then climbed to World No. 6 and won three singles titles. On November 1, 2007, after suffering from injuries for much of the year, Hingis announced her retirement from tennis while admitting she had tested positive for cocaine during Wimbledon in 2007. She denied using the drug. On January 4, 2008, she was banned from tennis for two years due to the cocaine offense.