Leo Albert Jozef "Lei" Clijsters (9 November 1956 – 4 January 2009) was a Belgian professional footballer, who played as a central defender.

Throughout his extensive senior career, the tough stopper was mainly associated with KV Mechelen, with whom he won the UEFA Cup Winners' Cup and the UEFA Super Cup. Also a prominent member of the Belgian national team, he was the father of tennis players Kim and Elke Clijsters.

Clijsters, a native of Opitter, started his football career with local Opitter FC. Later, he played for Club Brugge KV, but left the club after a disappointing two-year stint; he started his career as a midfielder.

Subsequently, Clijsters represented K.S.K. Tongeren, K. Patro Maasmechelen, K. Waterschei S.V. Thor Genk, KV Mechelen and R.F.C. de Liège. With Mechelen, he won the Belgian Cup in 1987, going on to conquer the subsequent UEFA Cup Winners' Cup and European Super Cup. He added the Belgian League in 1988–89, always as club captain.

In 1988, Clijsters also won the Golden Shoe award as league's MVP, and eventually retired with Liège at almost 37. Immediately, he starting working as a manager with former club Patro Eisden, then moving to K.A.A. Gent,K.F.C. Lommel S.K. (July–December 1998), K. Tesamen Hogerop Diest (two spells, in 1999–2000 and November 2000 – June 2001) and Mechelen (July–November 2000).

Kim Antonie Lode Clijsters (Dutch pronunciation: [kɪm ˈklɛistərs] ( listen); born 8 June 1983) is a Belgian professional tennis player. As of 28 May 2012, Clijsters is ranked no. 47 in singles. 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.