Steffi Graf plays tennis professionally.
The list of WTA number 1 ranked players shows the professional women 's tennis players who have been or currently are ranked world No. 1 by the Women 's Tennis Association , along with the dates of first reaching and losing that spot . Stefanie Maria `` Steffi '' Graf ( [ ˈʃtɛfiː ˈgʁa : f ] ; born 14 June 1969 ) is a German former tennis player , who was ranked world No. 1 during her career . Graf won six French Open singles titles ( second to Evert ) , seven Wimbledon singles titles , four Australian Open titles , and five U.S. Open singles titles .