Williams, 32, has amassed 13260 points to command the standings ahead of Belarussian Victoria Azarenka (8046) and Li Na of China (6045), who climbed into a career-high third for reaching the WTA Championships final she lost against Williams on Sunday.
Williams won 11 tournaments, including the French Open, US Open and the wrap-up in Istanbul, in her best season and was assured of a fourth prestigious year-ending No1 ranking for weeks. She also became the first woman to earn more than $12-million in prize money.
"It was an awesome year of tennis. To end with the Billie Jean King trophy after everything we have celebrated this year... it's just really exciting," Williams said.
Li rose from fifth to third at the expense of Russian Maria Sharapova and Poland's Agnieszka Radwanska in what was the only change in the top 10.
Meanwhile, Rafael Nadal has maintained first place in the men's tennis rankings, topping the ATP list with 11670 points from Serbia's Novak Djokovic (11120) and fellow Spaniard David Ferrer (6600). Nadal, Djokovic, Ferrer, Andy Murray, Juan Martin del Potro and Tomas Berdych qualified for the next week's season-ending World Tour Finals in London.
With Murray sidelined with injury, three more places are up for grabs - currently occupied by Roger Federer, Stansilas Wawrinka and Richard Gasquet.
Women's top 10 released yesterday (previous ranking in parenthesis): 1 (1) Williams, 2 (2) Azarenka, 3 (5) Na, 4 (3) Sharapova (5891), 5 (4) Radwanska (5875), 6 (6) Petra Kvitova, Czech Republic (4750), 7 (7) Sara Errani, Italy (4435), 8 (8) Jelena Jankovic, Serbia (4170), 9 (9) Angelique Kerber, Germany (3965) and 10 (10) Caroline Wozniacki, Denmark (3520).
lMen's rankings 1 (1) Nadal, 2 (2), Djokovic, 3 (3) Ferrer, 4 (4) Murray, Britain (6280), 5 (5) Del Potro, Argentina (5365), 6 (6) Federer, Switzerland (4245), 7 (7) Berdych, Czech Republic (4180), 8 (8) Wawrinka, Switzerland (3240), 9 (9) Tsonga, France (3235) and 10 (10) Gasquet, France (3 130).
