Stefanie Maria Graf (born June 14, 1969, in Mannheim, West Germany) is a former World No. 1 ranked female tennis player from Germany. She is generally considered to be one of the greatest female tennis players of all time. Graf won 22 Grand Slam singles titles, more than any other male or female player has won during the open era (although Margaret Smith Court won 24 Grand Slam singles titles during a career that spanned before and after the start of the open era).
In 1988, Graf became the only male or female player to win the "Golden Slam" capturing all four Grand Slam singles titles and the Olympic gold medal in the same year. She was ranked the Women's Tennis Association's No. 1 player for a record 377 weeks (the longest of any male or female player since rankings began) and is the only male or female player to have won all four Grand Slam singles tournaments (Wimbledon, the U.S. Open, the French Open and the Australian Open) at least four times each.
A notable feature of Graf's game was her versatility across all playing surfaces, exemplified by her winning six French Open singles titles (second to Chris Evert) and seven Wimbledon singles titles (third behind Martina Navratilova and Helen Wills Moody).
She is the only singles player, male or female, to have achieved a true Grand Slam across all three types of tennis courts, as the other five true singles Grand Slams occurred when the Australian and U.S. Opens were still played on grass. Graf reached thirteen consecutive Grand Slam singles finals, from the French Open in 1987 through the French Open in 1990, winning nine of them. She played in 36 Grand Slam singles tournaments from the 1987 French Open through the 1996 US Open, reaching the finals 29 times and winning 21 titles. Graf is married to the former World No. 1 men's tennis player Andre Agassi.