Naomi Osaka, Serena and Venus Williams top Forbes' 2021 Highest-Paid Female Athletes list

Despite women athletes still fighting ongoing pay disparities, progress is being made on the financial front—at least in professional tennis. Five WTA standouts landed among the Top 10 of Forbes' Highest-Paid Female Athletes list for 2021 and represent the massive upward movement for women in sports.

It's no surprise that Naomi Osaka ranked No. 1. She owns a vast array of sponsorships and serves as a brand ambassador for companies such as Louis Vuitton, sweetgreen and TAG Heuer. In 2021, she also collaborated with Levis, Frankies Bikinis and Beats by Dre. Not to mention that the 24-year-old released a Netflix documentary and launched her skincare brand, Kinlo, all while being an advocate for mental health.

So just how much did Osaka rake in? A whopping $57.3 million.

Coming in just behind the four-time Grand Slam winner is Serena Williams, who earned $45.9 million in 2021. The 40-year-old played even less than Osaka last year, which meant her ranking took a significant hit. But that didn't bother advertisers one bit. She partnered with Nike, Gatorade, DirecTV and served as executive producer for King Richard—the biopic centered around her father Richard.

Still not feeling 100 percent physically, she opted out of Australia and her return to court remains unclear.

Osaka and Serena are far above the rest of the women on the list, even the No. 3—Venus Williams—who collected $11.3 in total earnings. The seven-time Slam winner showed she is much more than a tennis star with her array of side hustles. She will join sister Serena in skipping this year's Aussie Open which marks the first time since 1997 that neither of them will compete at the event.

Garbine Muguruza also found a spot on the list and sits in the No. 5 position. The Spaniard was back to her winning ways in 2021 which triggered even more partnerships, including with Nivea and Jaguar.

No other women's tennis player made more than world No. 1 Ash Barty on the court. The Aussie's racquet did essentially all of the money-making for her in 2021—she's No. 8 on the Forbes list—which reflects the massive pay disparities that are still alive in the sport. When she won the Western & Southern Open last year, Barty earned $255,220, whereas men's champion Alexander Zverev took home $654,815. All in all, Barty earned $6.9 million.

Barty's racquet is already making money moves in 2022 as she claimed her first tournament of the season in Adelaide last week.