Serena Williams
At the age of 30, and despite having to recover from a blood clot on her lung in 2011, Serena Williams enjoyed one of her greatest years, winning Wimbledon for a fifth time, the US Open for a fourth time and winning both Olympic singles and doubles gold medals, with sister Venus.
She dropped only 17 games in six matches in the singles and beat Maria Sharapova 6-0, 6-1 in the final. It was a remarkable tour de force and made her only the second player after Steffi Graf to win the so-called Career Golden Grand Slam of all four Grand Slam tournaments during her career and the Olympic singles gold medal.
She is the only player in history to have won the Career Golden Grand Slam in singles and doubles. Her current total of 15 Grand Slam singles titles is now fourth in the open era behind Graf (22), Chris Evert (18) and Martina Navratilova (18). She rounded off the year by winning her third WTA Championship in October.