Claim: Serena Williams has a sibling.

Serena Jameka Williams -LRB- born September 26 , 1981 -RRB- is an American professional tennis player . The Women 's Tennis Association -LRB- WTA -RRB- has ranked her world no. 1 in singles on eight occasions , from 2002 to 2017 . She became the world no. 1 for the first time on July 8 , 2002 . On the sixth occasion , she held the ranking for 186 consecutive weeks , tying the record set by Steffi Graf for the most consecutive weeks as world no. 1 by a female tennis player . In total , she has been world no. 1 for 319 weeks , which ranks her third in the Open Era among female tennis players . Williams ' accomplishments and success in professional tennis have led some commentators , players , and sports writers to regard her as the greatest female tennis player of all time .   Williams holds the most Grand Slam titles in singles , doubles , and mixed doubles combined amongst active players . Her record of 39 Grand Slam titles puts her third on the all-time list and second in the open era : 23 in singles , 14 in women 's doubles , and 2 in mixed doubles . She is the most recent female player to have held all four Grand Slam singles titles simultaneously -LRB- 2002 -- 03 and 2014 -- 15 -RRB- and the third player to achieve this record twice after Rod Laver and Steffi Graf . She is also the most recent player , together with her sister Venus Williams , to have held all four Grand Slam women 's doubles titles simultaneously -LRB- 2009 -- 10 -RRB- .   Her total of 23 Grand Slam singles titles marks the record for the most Grand Slam wins by a tennis player in the Open Era , and is second on the all-time list behind Margaret Court -LRB- 24 -RRB- . She is the only tennis player in history -LRB- man or woman -RRB- to have won singles titles at least six times in three of the four Grand Slam tournaments , and the only player ever to have won two of the four Grand Slams seven times each -LRB- seven Wimbledon titles and seven Australian Open titles -RRB- . She is also the only tennis player to have won 10 Grand Slam singles titles in two separate decades . She has won an all-time record of 13 Grand Slam singles titles on hardcourt . Williams holds the Open Era record for most titles won at the Australian Open -LRB- 7 -RRB- and shares the Open Era record for most titles won at the US Open with Chris Evert -LRB- 6 -RRB- . She also holds an all-time record for the most singles matches won at the Grand Slams -LRB- man or woman -RRB- with 316 matches -LRB- through the 2017 Australian Open -RRB- .   She has won 14 Grand Slam doubles titles with her sister Venus , and the pair are unbeaten in Grand Slam doubles finals . As a team , she and Venus have the third most women 's doubles grand slam titles , behind the 18 titles of Natasha Zvereva -LRB- 14 with Gigi Fernández -RRB- and the record 20 titles won by Martina Navratilova and Pam Shriver . Williams is also a five-time winner of the WTA Tour Championships in the singles division . Serena has also won four Olympic gold medals , one in women 's singles and three in women 's doubles -- an all-time record shared with her sister , Venus . The arrival of the Williams sisters has been credited with ushering in a new era of power and athleticism on the women 's professional tennis tour . Williams was the highest paid female athlete in 2016 , earning $ 28.9 million in prize money and endorsements . She has won the Laureus Sportswoman of the Year award three times -LRB- 2003 , 2010 , 2016 -RRB- , and in December 2015 , she was named Sportsperson of the Year by Sports Illustrated magazine .