"I have never liked the word retirement," Williams wrote in a self-penned Vogue article. "It doesn't feel like a modern word to me. I've been thinking of this as a transition but I want to be sensitive about how I use that word, which means something very specific and important to a community of people.
"Maybe the best word to describe what I'm up to is evolution. I'm here to tell you that I'm evolving away from tennis, toward other things that are important to me.
"A few years ago I quietly started Serena Ventures, a venture capital firm. Soon after that, I started a family. I want to grow that family."
"But I’ve been reluctant to admit to myself or anyone else that I have to move on from playing tennis.
"One thing I’m not going to do is sugarcoat this. I know that a lot of people are excited about and look forward to retiring, and I really wish I felt that way. Ashleigh Barty was number one in the world when she left the sport this March, and I believe she really felt ready to move on. Caroline Wozniacki, who is one of my best friends, felt a sense of relief when she retired in 2020.
"There is no happiness in this topic for me. I know it’s not the usual thing to say, but I feel a great deal of pain. It’s the hardest thing that I could ever imagine. I hate it.
"I hate that I have to be at this crossroads. I keep saying to myself, I wish it could be easy for me, but it’s not. I’m torn: I don’t want it to be over, but at the same time I’m ready for what’s next."
Williams has been taking part in the Canadian Open in Toronto this week, winning her first match since the French Open in June. She is using the tournament as tune-up for the US Open, which gets under way at the end of August, in what could be her last Grand Slam.
During a more than two-decade long career, Williams has been an icon of the sport, winning 98 WTA Singles titles and spending 319 weeks at number one in the world rankings. She has also won four Olympic gold medals, one in the singles event and three with her sister Venus Williams (42), who she won multiple Grand Slam Doubles titles with too.
She finished her Vogue article by saying: "I’m terrible at goodbyes, the world’s worst. But please know that I am more grateful for you than I can ever express in words. You have carried me to so many wins and so many trophies.
"I’m going to miss that version of me, that girl who played tennis. And I’m going to miss you."
After the article dropped, Williams took to social media to confirm that she will indeed be retiring in the near future, although no date was given.
She said: "There comes a time in life when we have to decide to move in a different direction. That time is always hard when you love something so much. My goodness do I enjoy tennis. But now, the countdown has begun... I am gonna relish these next few weeks."
With the US Open just weeks away, her article and social media post puts added significance on the tournament - which you can follow with Flashscore.