Top Seven Highest-Paid Female Tennis Stars

The Forbes list of the world's highest-paid female athletes was recently released, and to nobody's surprise, tennis players claimed most of the spots. Tennis is the one sport where the prize money and popularity is relatively equal between the sexes, and lucrative endorsement contracts are readily available.

Let's take a look at the top seven female tennis players in terms of earnings.

1. Maria Sharapova

Sharapova leads the list of highest-earning female athletes for an amazing 11th straight year. She bounced back from injuries in 2013 to take the 2014 French Open, and racked up $6.7 million in prize money for the 2015 evaluation period. Sharapova also earns $23 million in endorsements from Avon, Evian, Tag Heuer, Nike, Head, Porsche and other sponsors, giving her the undisputed title at $29.7 million. That total is ahead of all but three male tennis stars.

2. Serena Williams

Serena is on a roll, with four straight Grand Slam wins (aka the Serena Slam). With a US Open victory, she would complete the calendar year sweep of the Grand Slam, a feat last pulled off by Steffi Graf in 1998. Her $11.6 million in prize money tops the list, and with $13 million in endorsements, Serena is closing in on the top earnings spot with $24.6 million. Chase (NYSE:JPM) and Gatorade/PepsiCo (NYSE:PEP) are among her sponsors.

3. Caroline Wozniacki

Wozniacki was involved in two high profile events other than tennis over the past year, with an appearance in the Sports Illustrated swimsuit issue, and a run in the New York City marathon that raised over $80,000 for charity. Wozniacki pulled in a total of $14.6 million with $11 million in endorsements and $3.6 million in prize money. Sponsors include Rolex, Adidas, and Godiva chocolates. (It's been reported that free chocolates are part of the deal.)

4. Ana Ivanovic

Ivanovic earned $8.3 million over the past year, with $1.8 million in winnings and $6.5 million in endorsements. She reached 5th in the 2014 world rankings in 2014 but has no Grand Slam victories since her triumph in the 2008 French Open. Ivanovic's sponsors include Adidas, Shiseido, and Dubai Duty Free.

5. Petra Kvitova

Thanks to a 2014 Wimbledon victory, Kvitova shot up the earnings list. As of this writing, her Wimbledon victory is the last Grand Slam event won by anyone other than Serena Williams. Kvitova's total winnings were $5.9 million, and an extra $1.8 million in endorsements raised her to 5th place with $7.7 million. Nike (NYSE:NKE) and Wilson are Kvitova's primary sponsors.

6. Simona Halep

Halep rose to be the second-ranked female player in 2014, propelled by her appearance in the finals of the 2014 French Open. She has multiple endorsements in her native Romania along with contracts with Adidas and Wilson, but $5.3 million in prize money overshadowed her $1.5 million in endorsements. With a total of $6.8 million, Halep is in 7th place on the Forbes list.

7. Agnieszka Radwanska

Radwanska earned $6 million over the last year, with $2 million in prize money and $4 million in endorsements. She has yet to break through with a Grand Slam victory, coming closest in 2012 at Wimbledon where Serena Williams beat her in the finals. Her sponsors include Lotto and Lexus.

Will Serena finally secure enough endorsements to catch Sharapova, or will Sharapova hold her title as the highest-earning female athlete for an amazing 12th straight year? Or will one of the other top ladies of tennis break out of the pack to challenge both? We'll have to see how the next 12 months play out.