Mats Wilander was born on 22 August 1964 in southern Sweden; Wikipedia gives his birthplace as Alvesta in its summary and as Växjö in the article text. As a junior he won the French Open boys' title, the European under-16 and under-18 championships and the Orange Bowl under-16 event, and he made his tour debut at Båstad in 1980.
Two years later he arrived at Roland Garros unseeded and beat Ivan Lendl, Vitas Gerulaitis, José Luis Clerc and Guillermo Vilas to win the 1982 French Open at 17 years and nine months, then the youngest man to win a Grand Slam singles title. In his semifinal against Clerc he gave a match point back to his opponent after a wrong call, a gesture that earned him the Pierre de Coubertin World Fair Play Trophy. He won the Australian Open on grass in 1983 and 1984, the French Open again in 1985, and in 1986 the Wimbledon doubles with Joakim Nyström.
At first he was a pure baseliner, but he kept adding to his game: volleys and lobs in 1985, then a stronger serve and a one-handed slice backhand in 1987. The work paid off in 1988, his finest season. He won the Australian Open on hard courts, beating Pat Cash 8–6 in the fifth set, the French Open against Henri Leconte and the US Open against Lendl in a five-set final, which took him to world No. 1 on 12 September 1988. He stayed there for 20 weeks and was named ITF World Champion.
Over his career he reached 11 major finals, won seven of them and collected 33 singles titles. Lendl was his main rival, with John McEnroe, Cash and Stefan Edberg also prominent. With Sweden he won the Davis Cup in 1984, 1985 and 1987; in 1983 he won both his singles rubbers in the final, but Australia won the tie.
Wilander played his last match in October 1996 in Beijing. Afterwards he coached Tatiana Golovin and Paul-Henri Mathieu in 2007, captained Sweden's Davis Cup team and became a commentator for Eurosport. He was inducted into the International Tennis Hall of Fame in 2002.