NEW YORK (AFP) - Real Madrid star Cristiano Ronaldo and Barcelona striker Lionel Messi topped the Forbes magazine list of the world's highest-paid athletes on Wednesday in the wake of boxer Floyd Mayweather's retirement and back surgery for golfer Tiger Woods.

The annual list of total revenues for top sports stars had been topped 12 times by Woods and in three of the last four by Mayweather, who retired unbeaten last year.

This year, 31-year-old Portugal forward Ronaldo topped the list at US$88 million (S$118 million) with US$56 million in salary and US$32 million more from endorsement deals.

The three-time Fifa player of the year is a marketing juggernaut with a new Nike deal worth US$13 million annually plus endorsement partners such as Tag Heuer and Herbalife plus his own lines of suits, cologne, shirts, shoes, underwear and hotels.

Messi, who sat out Argentina's opening victory at the Copa America Centenario this week, was next at US$81.4 million, with US$28 million of that from sponsorships.

LeBron James, who leads the Cleveland Cavaliers against defending champion Golden State in the ongoing NBA Finals, was third on the list and tops among Americans with US$77.2 million.

He has endorsement deals of US$54 million, including a lifetime pact with Nike that could pay off to the tune of US$1 billion, and US$23.2 million in club salary.

James made his movie debut in Trainwreck last year and is set to star in the sequel to the 1996 Michael Jordan film Space Jam, as well as take a huge salary boost next year when the NBA's new US$24 billion television deal starts.

Golden State's Stephen Curry, the NBA Most Valuable Player and scoring champion, shared 69th on US$23.6 million with world number one golfer Jason Day of Australia.

Roger Federer, the Swiss tennis star with a record 17 men's Grand Slam singles titles, was fourth on US$67.8 million. He set the pace in sponsor income at US$60 million.

Television rights fee hikes helped fuel team sport stars, boosting the top-100 cutoff to US$20.8 million, US$2 million more than last year. The study time frame runs for the 12 months ending one week ago.

The top 100 include 65 Americans and athletes from 22 other nations encompassing 10 sports, with the most from baseball at 26.

Together the top 100 took home a combined US$3.15 billion, 29 per cent of it from endorsements and appearances.

The 2015 leaders, Mayweather and Filipino icon Manny Pacquiao, both sank with the end of their ring careers. Mayweather dipped to 16th with US$44 million in earnings while Pacquiao was 63rd at US$24 million.

World number one Serena Williams, runner-up at this years French and Australian Opens, was the highest earning woman at US$28.9 million, 40th overall, with doping-banned Russian tennis star Maria Sharapova 88th on US$21.9 million.

Sixth overall on the list was Serbian Novak Djokovic, who cracked the top 10 for the first time at US$55.8 million, with US$34 million in endorsements. Djokovic won the French Open last Sunday to claim his fourth consecutive men's Grand Slam singles title and complete a career Grand Slam.

Kobe Bryant, the Los Angeles Lakers star who retired after this past season, was 10th on US$50 million, evenly split between salary and sponsorships.

British Formula One racer Lewis Hamilton was 11th on US$46 million, only US$4 million from endorsements.

Former world number one Woods, a 14-time major golf champion, was 12th on US$45.3 million, all but about US$274,000 of it from sponsorship deals.

Northern Ireland golfer Rory McIlroy was 17th at US$42.6 million, Spanish tennis star Rafael Nadal and Brazilian footballer Neymar shared 21st at US$37.5 million.

Jamaica's Usain Bolt, who seeks more Olympic athletics sprint gold in two months at Rio, was 32nd at US$32.5 million.