Tennis aces score on court, reap reward in wealth: The 10 wealthiest players

On Monday, the U.S. Open—the crown jewel of grand slam tennis and a big money maker for the metro New York City region—kicked off, featuring some of the biggest names in the sport. The event itself is said to dwarf the Super Bowl in its regional economic impact, bringing in more than $700 million.

For the athletes appearing on its courts, the tournament is widely considered to be the most lucrative in terms of prize money, beating out awards at its Australian and French counterparts, as well as Wimbledon.

Read More Who's the most marketable tennis player?

The men's and women's singles champions at the U.S. Open 2015 will play for $3.3 million in prize money, not including the possibility of additional earnings. Yet according to Wealth-X Professional, they probably don't need the money. The wealth intelligence site compiled a list of the top 10 wealthiest (active) players, according to their net worth, which CNBC compiled in the following slides.

—By Carolina Cruz, special to CNBC.com
Posted 31 Aug. 2015

The 34-year-old Swiss native is a household name who is arguably tennis' most popular male player. The man who began his career at age 12 saw his star rise after he dethroned Pete Sampras, the singles champion at the time, at Wimbledon in 2001. A big chunk of Federer's wealth is derived from big brand sponsorships and endorsements, having deals with Nike, Rolex, Gillette and Mercedes-Benz, among others.

The Russia-born Sharapova is notorious for both her competitive play and the shrieks she emits while doing so, which reportedly reach 109 decibels. She made history as the first woman to carry Russia's flag at the opening ceremony of an Olympic Games in 2012. Maria has a raft of endorsements to her credit, including Canon, Gatorade, Motorola, Colgate-Palmolive and Honda. She even signed a modeling contract with IMG Worldwide's modeling division. In 2012 Sharapova co-founded Sugarpova, a tennis-themed candy treat.

This U.S. Open could very well be a historical milestone for Williams, who is poised to be the first player since Steffi Graf to win all major slam tournaments in a calendar year.

Although still in her prime, the No. 1-ranked player is already being mentioned alongside all-time greats such as Martina Navratilova, Margaret Court and Chris Evert-Lloyd. She began playing at age 4, when her parents opted for homeschooling so she and her sister, Venus, could focus on their games. Her talent and tenacity have earned her 21 Grand Slam singles titles and major sponsorships such as Nike, Gatorade and Wilson.

Djokovic, a Serbian who first turned pro a little over a decade ago, has won nine major singles and is ranked as the top player in men's singles tennis. He's also one of a small club of male players to win multiple Grand Slam titles. Djokovic is a published author, is involved in his family's business and has endorsement deals that include Adidas, FitLine and Peugeot.

The Spaniard is known as the King of Clay for his numerous wins on this type of court. Since turning professional at 15, Nadal has a host of accomplishments, including 14 Grand Slam singles titles and a record 27 titles—and he's not even 30. However, in 2013, he struggled with frequent injuries and appendicitis that resulted in a dip in his tennis ranking and earnings. His endorsements include Tommy Hilfiger and Telefonica.

The four-time Olympic gold medalist was groomed from an early age, alongside her younger sister, to be a tennis pro. The No. 23-ranked player has numerous wins that helped land her a major endorsement deal valued at $40 million over a five-year span with Reebok. Williams was forced to slow down when diagnosed with Sjögren's Syndrome, but still maintains outside business ventures such as V-Starr Interiors and as EleVen by Venus, an active wear company.

The No. 3-ranked player brought his homeland great joy by ending a 100-year drought for Britain in the singles championship category. At the 2012 U.S. Open, the 28-year-old became the first Brit since 1977 and the first in nearly 80 years to win at Wimbledon. The 28-year old's likeness graces four U.K. stamps that commemorate his Wimbledon victory. His endorsements include a $23 million contract with sportswear company Under Armour.

This Belarusian and two-time grand slam player fell into tennis at the age of 7 and turned pro in 2003. The former No. 1 player, now ranked 24, has won at the Australian Open twice, in 2012 and 2013. The 26-year-old has netted nearly $25 million in career prize money, and is currently in deals with Nike, American Express and Citizen Watch.

The 25-year-old Denmark native has yet to win at any of the major tournaments, yet is still ranked among the top 30 players and has an ongoing competitive rivalry with Serena Williams. She ranked No. 1 for more than a year, but has won 23 other titles. Wozniacki has posed for Sports Illustrated's famed Swimsuit Edition, and has reaped endorsement dollars from Godiva, Rolex and Adidas, among others.

Although Ivanovic made an early exit from the 2015 U.S. Open, the 27-year-old Serbian has numerous accomplishments to her credit. The No. 6 player has won 15 singles titles, which includes one Grand Slam, and at various times has defeated a number of top-seeded players, including both Williams sisters, Sharapova and Azarenka. Ivanovic has earned just over $14 million in career money, but her biggest endorsement comes from Adidas, where she is contracted for the remainder of her career and beyond.