Kim Antonie Lode Clijsters (; born 8 June 1983) is a retired Belgian professional tennis player. Clijsters is a former World No. 1 in both singles and doubles.
Clijsters has won 41 WTA singles titles and 11 WTA doubles titles. She has won four Grand Slam singles titles: three at the US Open, in 2005, 2009, and 2010 and one at the Australian Open in 2011. She has also been runner-up in four Grand Slam singles tournaments, and won the WTA Tour Championships singles title in 2002, 2003, and 2010. In doubles, she won the French Open and Wimbledon titles in 2003. Clijsters announced her retirement with immediate effect on 6 May 2007, but almost two years later, on 26 March 2009, she publicly declared her intent to return to the WTA tour for the 2009 summer hard court season. In only her third tournament back, she won her second US Open title, becoming the first unseeded player and wildcard to win the tournament, and the first mother to win a major since Evonne Goolagong in 1980.
In June 2011, TIME magazine named her one of the "30 Legends of Women's Tennis: Past, Present and Future". According to Forbes in August 2011, she became the fifth highest-paid female athlete over the past year.
On 20 May 2012, Clijsters, who had previously announced that 2012 would be her last season, revealed that she would retire after the US Open. On 29 August 2012, Clijsters played her last singles match of her career at the 2012 US Open where she lost in the second round. On 1 September, she played her last (mixed) doubles match with Bob Bryan, losing in the second round.