Serena Williams says she will retire from tennis sometime after the U.S. Open.

The world first came to know Serena Williams as a 17-year-old with beaded braids, overwhelming power and precocious intelligence and poise when she stunned her sport by winning the first of her 23 Grand Slam singles titles at the 1999 U.S. Open.

So began a journey that, with plenty of help from her sister Venus and her trailblazing parents, changed the game, transcended tennis and turned Williams into a beacon of fashion, entertainment and business, shifting the way people inside and outside of sports viewed female athletes.

On Tuesday, Williams set the stage for the tennis part of that journey to conclude at the Billie Jean King National Tennis Center and the U.S. Open, where it began so many championships, battles, fist pumps and screams of “Come on!” ago.

In a first-person article in the famed September issue of Vogue, published online on Tuesday, Williams said that she planned to retire from the sport after playing in the U.S. Open, which begins later this month, for the 21st time. And as she has for more than two decades, Williams made the announcement with her own unique twist, stating in the as-told-to cover story that she has “never liked the word retirement,” and preferred the word “evolution” to describe her next steps.

“I’m evolving away from tennis, toward other things that are important to me,” including working with her venture capital firm and growing her family, she said.

Williams was not explicit about when she might stop playing, but she hinted on Instagram that the U.S. Open could be her last tournament while leaving the door ever-so-slightly open to continue, or to come back, as players who retire often do. “The countdown has begun,” she said, adding, “I’m gonna relish these next few weeks.”

Williams is playing this week at a U.S. Open tuneup tournament in Toronto and is scheduled to play in Cincinnati during the next week.

Asked Monday after her straight-sets win over Nuria Parrizas-Diaz of Spain what motivated her now, Williams said “the light at the end of the tunnel.”

“Lately that’s been it for me,” she added. “I can’t wait to get to that light.”

Though some in tennis are skeptical that Williams will step away imminently, exiting the stage this year at the U.S. Open would be a fitting end to her storied career. Williams has won the singles title there six times, beginning in 1999, when she leapfrogged her older sister Venus to claim the family’s first Grand Slam championship 23 years ago, a number that matches her career Grand Slam tally. The tournament has also been the site of some of Williams’s lowest moments, including confrontations with umpires and tournament officials in the semifinals in 2009 and the finals in 2018.

Williams has won each of the Grand Slam tournaments at least three times.Credit…Asanka Brendon Ratnayake for The NYT; Chang W. Lee/NYT; David Vincent/AP; Daniel Berehulak/Getty

“It feels like the right exclamation point, the right ending,” said Pam Shriver, the former player and tennis commentator who was one of the great doubles champions of the 1980s. “It doesn’t matter her result.”

Williams’s tennis future has been in doubt since she was forced to retire minutes into her first-round match at Wimbledon last year after she tore her hamstring.

The injury sidelined her for nearly a year. In fact, Shriver and others thought it was likely that Williams might never officially retire but would instead continue the existence that she assumed for months following her teary Wimbledon exit.

This spring though, Williams said she had the urge to play competitively again. In the Vogue story, she stated that Tiger Woods persuaded her to commit to training hard for two weeks and see what transpired. She did not immediately take his advice but eventually began hitting and signed up for the doubles competition at a grass court tournament ahead of Wimbledon .

At Wimbledon, she played a spirited but inconsistent three-hour, first-round match, losing to Harmony Tan of France, 7-5, 1-6, 7-6 (7). She showed flashes of the power and touch that had once made her nearly unbeatable, but lacked the fitness and match toughness that comes from being a regular on the WTA Tour.

Williams wrote that she and her husband, Alexis Ohanian, planned to have another child, though she lamented the choice between another child and her tennis career. She expressing envy that some male athletes, like the 45-year-old N.F.L. quarterback Tom Brady, could continue to compete while their female spouses had children.

“I definitely don’t want to be pregnant again as an athlete,” she said. “I need to be two feet into tennis or two feet out.”

Williams won her last Grand Slam tournament title while she was pregnant during the Australian Open in 2017.

Williams has won nearly $100 million in prize money, but her tennis career has hardly prevented her from pursuing her other interests. She has frequently helped design her tennis outfits. She was an executive producer of “King Richard,” the Oscar-winning film about her family that focused on how her father took two girls from Compton, Calif., to the pinnacle of sports. In recent years, she has become a venture capitalist, creating Serena Ventures, which invests in early stage ideas and companies, many in technology and run by women.

On the tennis court, for the moment, Williams remains second to Margaret Court of Australia in Grand Slam singles championships, a record she had many chances to tie and then surpass in 2018 and 2019 when she lost four Grand Slam finals without winning a set. However, because many of Court’s wins predate the modern era of professional tennis, that shortcoming is unlikely to tarnish Williams’s legacy as the greatest female tennis player, one of the greatest players, and one of the best athletes in any sport.

“When Serena steps away from tennis, she will leave as the sport’s greatest player,” said Billie Jean King, the champion and pioneer of sports. “After a career that has inspired a new generation of players and fans, she will forever be known as a champion who won on the court and raised the global profile of the sport off it.”

Beyond all the championships — Williams has won 73 singles titles, 23 in doubles, two in mixed doubles and has played on four Olympic teams, winning four gold medals — her impact on how the world perceives female athletes and inspiring the younger Black girls who now lead American women’s tennis may be her greatest legacies.

With a unique mix of power, strength, speed, touch and the tennis intelligence that produced her dominance, Williams made irrelevant the distinction between great male and female tennis players as no woman had done.

Rafael Nadal, Roger Federer and Novak Djokovic, the great male tennis players of the 21st century — and the greatest the men’s game has ever produced — spoke of Williams as one of them.

Last year at the U.S. Open, as the pressure mounted on Djokovic to win a rare calendar year Grand Slam, he said only Williams could understand what he was going through.

Williams came to the U.S. Open in 2015 having won the year’s first three Grand Slam singles titles but lost to the unseeded Roberta Vinci of Italy in the semifinals. Winning the title that year would have given her a fifth consecutive Grand Slam singles championship, since she had already won four consecutive Grand Slam singles titles for the second time, a feat now known as the “Serena Slam.”

None of this has surprised Rick Macci, the famed professional coach who three decades ago evaluated Serena and Venus Williams playing in a rundown park in Compton when Black girls, especially poor ones, rarely pursued tennis. At first Macci was not impressed, but when the girls started playing points everything changed.

“There was a rage inside these two little kids once we kept score,” Macci said in an interview Tuesday. “They ran so fast they almost fell down. I took a huge chance because of what I thought I saw on the inside, and I haven’t seen it since.”

Coco Gauff, the rising 18-year-old who is the latest Black American player to bear the burden of being labeled “the next Serena,” said Williams was “the reason why I play tennis,” after her win Tuesday in Toronto.

“I saw somebody who looked like me dominating the game,” Gauff, ranked 11th in the world, “It made me believe that I could dominate, too.”