Xavier Malisse (born 19 July 1980) is a retired Belgian tennis player. Born in the north-western Flemish city of Kortrijk and nicknamed X-Man, he is only one of two players from Belgium (the other being David Goffin) to have been ranked in the top 20 of the ATP tour, with a career-high singles ranking of World No. 19.
As a junior Malisse compiled a singles win/loss record of 66–18, reaching as high as No. 10 in the junior world singles rankings in 1997.
Malisse turned professional in 1998.
His best performance in Grand Slam singles competition was at the 2002 Wimbledon championships, where he reached the semi-final, beating Galo Blanco, Vince Spadea, Yevgeny Kafelnikov and Britain's Greg Rusedski in five sets en route, as well as former champion Richard Krajicek. He eventually lost to runner-up David Nalbandian, again in five sets. Malisse and Olivier Rochus won the French Open doubles championship in 2004. He has won three ATP tour singles titles: Delray Beach in 2005 and 2007, and Chennai in 2007.