Novak Djokovic broke Steffi Graf's record and has the longest streak at No. 1 at 378 weeks. Djokovic has won 22 Grand Slam titles so far.
German tennis legend Steffi Graf had second-longest streak as the world No. 1 at 377 weeks and won 22 Grand Slam titles.
Martina Navratilova had the third-longest streak as world No. 1 at 332 weeks, winning 18 singles Grand Slam titles.
American Serena Williams won 23 Grand Slams in his professional career and held the No. 1 rank for 319 weeks.
Swiss legend Roger Federer won 20 Grand Slam titles in his career and was world No. 1 for 310 weeks.
Former American star Pete Sampras won 14 Grand Slam titles and held the No. 1 position for 286 weeks.