Mats Arne Olof Wilander is a Swedish former world No. 1 tennis player. From 1982 to 1988, he won seven major singles titles (three at the French Open, three at the Australian Open, and one at the US Open), and one major men's doubles title (at Wimbledon). His breakthrough came suddenly and unexpectedly when he won the 1982 French Open at the age of 17.
In 1988, Wilander won three of the four singles majors and finished the year ranked as the world No. 1. Although he never won the singles title at Wimbledon, Wilander twice won the Australian Open when it was played on grass courts. This makes Wilander one of only six men (along with Jimmy Connors, Andre Agassi, Rafael Nadal, Roger Federer and Novak Djokovic) to have won major singles titles on grass courts, hard courts, and clay courts since it was first achievable in 1978 (when US Open was first played on hard courts). Wilander, Nadal, and Djokovic are the only men to have won at least two major singles titles on each of the three surfaces.
Wilander won his fourth major singles title at the age of 20, the youngest man in history to have achieved the feat. He also won eight Grand Prix Super Series titles (1983–88), the precursors to the current ATP Tour Masters 1000. He won 33 singles titles and seven doubles titles during his career. He was also a driving force behind Sweden's run of seven consecutive Davis Cup finals in the 1980s.
In 1983, Wilander won the Jerring Award.
In 2002, Wilander was inducted into the International Tennis Hall of Fame.