Stefanie Maria Graf (born June 14, 1969 in Mannheim, Germany) is a former World No. 1 woman tennis player from Germany. She is generally considered to be one of the greatest woman tennis players of all time. Graf won 22 Grand Slam singles titles. In 1988, she became the only player to achieve 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 player, male or female, since rankings began) and is the only player, male or female, to have won all four Grand Slam singles tournaments (Wimbledon, the US 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 6 French Open singles titles (second to Chris Evert) and 7 Wimbledon singles titles (third behind Martina Navratilova and Helen Wills).

Graf is married to the former World No. 1 men's tennis player Andre Agassi.