Serena Jameka Williams is an American former professional tennis player. She was ranked as the world No. 1 in women's singles by the Women's Tennis Association (WTA) for 319 weeks (third-most of all time), and finished as the year-end No. 1 five times. Williams won 73 WTA Tour–level singles titles, including 23 major women's singles titles—the most in the Open Era, and the second-most of all time. She is the only player to accomplish a career Golden Slam in both singles and doubles.
Along with her elder sister Venus, Serena Williams was coached by her parents Oracene Price and Richard Williams. Turning professional in 1995, she won her first major singles title at the 1999 US Open. From the 2002 French Open to the 2003 Australian Open she was dominant, winning all four major singles titles consecutively (each time over Venus in the final) to achieve a non-calendar year Grand Slam (nicknamed the "Serena Slam"). The next few years saw Williams capture two more major singles titles, but suffer from injury and decline in form. Starting in 2007, however, she gradually returned to form despite continued injuries, reclaiming the world No. 1 singles ranking.