Serena Williams competes in women's singles and doubles.
Serena Williams . The Women 's Tennis Association ( WTA ) has ranked her world no. 1 in singles on eight occasions , from 2002 to 2017 . 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 also holds an all-time record for the most singles matches won at the Grand Slams ( man or woman ) with 316 matches ( through the 2017 Australian Open ) . 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 .