Stefanie Maria Graf was born on 14 June 1969 in Mannheim, West Germany. Her father Peter, a former car and insurance salesman who became a regional player and then a coach, first put a wooden racket in her hands when she was three, and the family living room became her first court. He managed her schedule closely, limiting how much she played so that she would not burn out, and with him and her coach Pavel Složil she often practised up to four hours a day, going straight from airports to the courts.
Her first major title came at the 1987 French Open, when she was 17. In 1988 she did what no player had done before: she won all four majors and the Olympic gold medal in Seoul in the same calendar year, the Golden Slam. She remains the only player, man or woman, to have won each major singles title at least four times: four Australian Opens, six French Opens, seven Wimbledons and five US Opens, 22 major singles titles in all. She won at least one major every year until 1997.
Graf was ranked world No. 1 for a record 377 weeks, 186 of them in a row. Her game was built on footwork, versatility on every surface and a forehand so hard that it earned her the nickname "Fräulein Vorhand", Miss Forehand. She won 107 singles titles, third on the WTA's all-time list after Martina Navratilova and Chris Evert. In 1992 she replaced Složil with Heinz Günthardt, who stayed her coach until she retired.
In 1999 she won the French Open once more and then, that summer, announced her retirement at the age of 30. She married Andre Agassi in 2001. Since leaving the tour she has concentrated on Children for Tomorrow, the charitable foundation she set up, and on her sports management company.