Steffi Graf is a German former professional tennis player who was ranked world No. 1 in singles for a record 377 weeks. She won 22 Grand Slam singles titles, which is the most by any player in the Open Era, and is considered to be one of the greatest female tennis players of all time. Graf won seven French Open singles titles, six Australian Open singles titles, five Wimbledon singles titles, and four US Open singles titles. She also won the 1988 Olympic gold medal in women's singles.