Serena Jameka Williams is a professional American tennis player. Already regarded as one of the greatest female players of all time, her 30 Grand Slam titles place her ninth on the all-time list: 15 in singles, 13 in women's doubles, and 2 in mixed doubles. Her sheer power and athletic ability often overwhelm her opponents, and her sense of style and presence have made her a stand-out celebrity on the court. She is the most recent player, male or female, to have held all four Grand Slam singles titles simultaneously and only the fifth woman ever to do so. She was also the first woman, along with older sister Venus Williams, to hold all four Grand Slam doubles titles simultaneously since Martina Hingis did so in 1998. Her 15 Grand Slam singles titles tally is sixth on the all-time list. Williams ranks fourth in Grand Slam women's singles titles won during the Open Era, behind Steffi Graf (22 titles) and Chris Evert and Martina Navratilova (18 titles each). Among active players, male or female, she holds the most Major titles in singles, doubles, and mixed doubles. She won her 13 Grand Slam doubles titles with her sister Venus Williams and the pair is unbeaten in Grand Slam finals. Serena Williams is also a three-time winner of the WTA Tour Championships. Serena Williams has won four Olympic gold medals, one in women's singles and three in women's doubles. In 1999, she beat her sister in their race to the family's first Grand Slam win, when she captured the U.S. Open title. In 2012, she became the second player after Steffi Graf to win a career Golden Grand Slam after winning the gold medal at the 2012 Summer Olympics in Wimbledon.