Serena Jameka Williams (born September 26, 1981) is an American professional tennis player and the current World Number 1 ranked female player. She has been ranked World Number 1 by the Women's Tennis Association (WTA) on five separate occasions. She regained this ranking for the fifth time in her career on the 2 November 2009. She is the reigning champion in both singles and women's doubles at the Australian Open and Wimbledon and in doubles at the US Open. In total, she has won 25 Grand Slam titles: 12 in singles, eleven in women's doubles and two in mixed doubles. In addition, she has won two Olympic gold medals in women's doubles.She also has won more Grand Slam titles than any other active female player and has won more career prize money than any other female athlete in history.

Williams reached the top ten on the WTA world rankings for the first time in 1999 when she won several tournaments, including her first Grand Slam victory at the US Open at the age of 17. Between 2002 and 2003, Williams won five of the six Grand Slam events she entered, becoming the fifth woman in history to hold all four Grand Slam titles simultaneously. She became the World Number 1 for the first time in July 2002.

Williams' domination of the sport came to an abrupt end in mid-2003 when she had surgery to repair a partial tear in a knee tendon.Upon her return to the sport in 2004, her results were noticeably less consistent than previously. In early 2005, she won her first Grand Slam title in 18 months at the Australian Open, but a string of injuries then limited her to competing in just 13 events in the two years that followed, winning none of them. Her standing in the world rankings suffered as a result, the nadir being World Number 140 in July 2006, leading to widespread speculation that she had passed her peak.Williams, however, eventually won another Grand Slam title at the Australian Open in 2007, despite being ranked World Number 81 at the time. Williams returned to the top ten later that year and has since competed in every Grand Slam event. She became the World Number 1 for the first time in five years in September 2008. She was named female athlete of 2009 by the Associated Press.

Williams is the younger sister of fellow former World Number 1 professional female tennis player Venus Williams. They have played each other in 23 professional matches dating back to 1998, with Serena winning 13 of these matches as of October 2009. Their meeting in the final of the 2001 US Open was the first Grand Slam final contested by two sisters in the open era. As of July 2009, they have met in eight Grand Slam finals, with Serena winning six of those. Between the 2002 French Open and the 2003 Australian Open, they met in all four Grand Slam finals, the first time in the Open era that the same two players had contested four consecutive Grand Slam finals. The pair regularly team to play doubles and have won 11 Grand Slam titles together.

Williams won her fifth Australian Open title at the 2010 Australian Open, an Open era record, and in doing so won her 12th career Grand Slam singles title, tying her with Billie Jean King and Suzanne Lenglen for sixth on the all-time list.

Early life

Williams was born in Saginaw, Michigan to Richard Williams and Oracene Price. She is of African American heritage and is one of five sisters: Lyndrea, Yetunde (died September 14, 2003), Isha, and Venus.Her mother raised Williams and her other daughters as members of the Jehovah's Witnesses religious group. When the children were young, the family moved to the Los Angeles suburb of Compton, where Williams started playing tennis at the age of four.Her father home-schooled Williams and her sister Venus.To this end, Williams was and remains coached by both her parents.

Williams' family moved from Compton to West Palm Beach when she was nine so that she could attend the tennis academy of Rick Macci, who would provide additional coaching. Macci spotted the exceptional talents of the sisters. He did not always agree with Williams' father but respected that "he treated his daughters like kids, allowed them to be little girls".Richard stopped sending his daughters to national junior tennis tournaments when Williams was 10, since he wanted them to take it slow and focus on school work. Another motivation was racial, as he had allegedly heard parents of white players talk about the Williams sisters in a derogatory manner during tournaments.At that time, Williams had a 46–3 record on the United States Tennis Association junior tour and was ranked No. 1 among under 10 players in Florida.In 1995, Richard pulled his daughters out of Macci's academy, and from then on took over all coaching at their home. When asked in 2000 whether having followed the normal path of playing regularly on the junior circuit would have been beneficial, Williams responded: "Everyone does different things. I think for Venus and I, we just tried a different road, and it worked for us."