Sloane Stephens
Rank 3
Total earnings: $11.2 million
Right when her sponsorship deals were expiring, Stephens' won her first Grand Slam title – the 2017 US Open. The title led to a huge bump in new deals with Nike, Mercedes-Benz, Rolex, Colgate, Chocolate Milk and Biofreeze. Since 2002, she has been the American woman apart from the Williams sisters, to win a Grand Slam.