"I'm turning 41 this month, and something's got to give," Williams wrote in an essay released Tuesday by Vogue magazine.
Williams, one of the greatest and most accomplished athletes in the history of her — or any other — sport, said she does not like the word retirement and prefers to think of this stage of her life as "evolving away from tennis, toward other things that are important to me."
Williams is playing this week in Toronto, at a hard-court tournament that leads into the U.S. Open, the year's last Grand Slam event, which begins in New York on Aug. 29.
The American has won more Grand Slam singles titles in the professional era than any other woman or man. Only one player, Margaret Court, collected more, 24, although she won a portion of hers in the amateur era.
"I'd be lying if I said I didn't want that record. Obviously I do. But day to day, I'm really not thinking about her. If I'm in a Grand Slam final, then yes, I am thinking about that record," Williams said.
"Maybe I thought about it too much, and that didn't help. The way I see it, I should have had 30-plus Grand Slams."
But, Williams went on to write, "These days, if I have to choose between building my tennis resume and building my family, I choose the latter."
She and her husband, Reddit co-founder Alexis Ohanian, have a daughter, Olympia, who turns 5 on Sept. 1.
"Believe me, I never wanted to have to choose between tennis and a family. I don't think it's fair," said Williams, who was pregnant when she won the 2017 Australian Open for her last Grand Slam trophy.
"If I were a guy, I wouldn't be writing this because I'd be out there playing and winning while my wife was doing the physical labor of expanding our family."
Williams was off the tour for about a year after getting injured during her first-round match at Wimbledon in 2021. She returned to singles competition at the All England Club this June and lost in the first round.
After that defeat, Williams was asked whether she would compete again.
"That's a question I can't answer," she said at the time.
"I don't know. ... Who knows? Who knows where I'll pop up?"
Williams hints in the essay that the U.S. Open will be her last tournament but does not say so explicitly.
"I'm not looking for some ceremonial, final on-court moment," Williams wrote.
"I'm terrible at goodbyes, the world's worst."