She is the number 63 out of the 100.
The lack of female representation comes at a time when the issue of gender pay inequity in professional sports has gained attention and female players are willing to sue to put a spotlight on the disparity.
Williams, 37, reappeared on the list after Forbes calculated her pay at $29.2 million, as well as her winnings at $4.2 million and off-the-court endorsement deals at $25 million. Her sponsorships include Gatorade, Wilson Sporting Goods and JPMorgan Chase. She was also the only woman on the list in 2017.
Number one on the list is Argentine soccer star Lionel Messi, whose pay, winnings and endorsement earnings reached a total $254 million. The second and third spot is also taken by footballers - Cristiano Ronald and Neymar jnr. respectively.
Four other tennis players made the ranking, including Switzerland's Roger Federer, who reached No. 5 and earned a total of $186.8 million.
In general, the top athletes represent major sports in the United States and internationally: soccer, football, basketball and baseball. Mike Trout, the Los Angeles Angels center fielder who earlier this year reportedly signed what appeared to be the largest contract in professional sports history worth $430 million over 12 years, was No. 17 on this year's Forbes ranking.