Steffi Graf, German tennis player
Stefanie Maria "Steffi" Graf ( GRA(H)F, German: [ˈʃtɛfiː ˈɡʁaːf] (listen); born 14 June 1969) is a German former professional tennis player. She was ranked world No. 1 for a record 377 weeks and won 22 major singles titles, the second-most since the start of the Open Era in 1968 and third-most of all-time (behind Margaret Court's 24 and Serena Williams' 23). In 1988, Graf became the first tennis player to achieve the Golden Slam by winning all four major singles titles and the Olympic gold medal in the same calendar year. Furthermore, she is the only tennis player, male or female, to have won each major at least four times.

Graf was ranked singles world No. 1 by the Women's Tennis Association (WTA) for a record 377 total weeks: the longest period for which any player, female or male, has held a singles number-one ranking since the WTA and the Association of Tennis Professionals, respectively, began issuing rankings. She won 107 singles titles, which ranks her third on the WTA's all-time list after Martina Navratilova (167 titles) and Chris Evert (157 titles). She and Margaret Court are the only players, female or male, to win three majors in a calendar year five times (1988, 1989, 1993, 1995 and 1996).

Notable features of Graf's game were her versatility across all playing surfaces, footwork and powerful forehand drive. Graf's athletic ability and aggressive game played from the baseline have been credited with developing the modern style of play that has come to dominate today's game. She won six French Open singles titles (second to Evert), seven Wimbledon singles titles, four Australian Open titles, and five US Open singles titles. She is the only singles player (male or female) to have achieved a Grand Slam across three surfaces (grass, clay, and hard courts). Graf reached 13 consecutive singles major finals from the 1987 French Open to the 1990 French Open, winning nine of them. She won five consecutive singles majors (1988 Australian Open to 1989 Australian Open), and seven out of eight, in two calendar years (1988 Australian Open to 1989 US Open, except 1989 French Open). She reached a total of 31 singles major finals.

Graf retired at the age of 30 in 1999 while she was ranked world No. 3. She is regarded as one of the greatest female tennis players of all time. Martina Navratilova included Graf at the top of her list of the greatest players ever. In the year of Graf's retirement, Billie Jean King said, "Steffi [Graf] is definitely the greatest women's tennis player of all time." In December 1999, Graf was named the greatest female tennis player of the 20th century by a panel of experts assembled by the Associated Press. She married former world No. 1 men's tennis player Andre Agassi in October 2001. They have two children. Graf was inducted into the Tennis Hall of Fame in 2004. Along with Boris Becker, Graf was considered instrumental in popularizing tennis in Germany, where it remains one of the foremost national sports.