No women made the 2018 Forbes 100 highest-paid athletes list

Tennis champion Serena Williams, the only woman to have made last year's list, didn't make the income cut on the 2018 roundup, likely because she was unable to compete for most of 2017 due to her pregnancy. She gave birth to a daughter last September and just played her first major tournament since she became a mother.

Even so, Forbes reported that Williams earned an estimated $18 million last year because of deals with the likes of Nike, JPMorgan Chase, Gatorade and others. However, that was about $5 million less than NBA player Nicolas Batum, who landed the 100th spot on the list.

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Topping this year's list is boxer Floyd Mayweather, who earned $285 million last year, followed by soccer players Lionel Messi at $111 million and Cristiano Ronaldo at $108 million.

The top ten were rounded out by mixed martial arts star Conor McGregor at $99 million, soccer player Neymar at $90 million, Cleveland Cavaliers star LeBron James at $85.5 million, tennis player Roger Federer at $77.2 million, Golden State Warriors guard Stephen Curry at $76.9 million and NFL quarterbacks Matt Ryan and Matthew Stafford at $67.3 million and $59.5 million, respectively.

According to Forbes, the earnings reported on the list include prize money, salaries, bonuses and endorsement incomes accrued between June 1, 2017 and June 1, 2018.

While the time off Williams took for pregnancy and maternity leave affected her total take-home, the same is not true for the fathers on the list, who could still compete during their partners' pregnancies.

Of the men who landed in the top 10, Messi became a father for the third time this past March, Ronaldo welcomed twins last June and Ryan's wife gave birth to twins in April. Curry and Stafford's wives are currently pregnant; each is expecting the couple's third child.