The 44-year-old Williams, a 23-time Grand Slam singles champion, has not played since a third-round loss at the 2022 US Open.
Williams posted the message, "Good news travels fast" along with a video of her on court in an all-white Nike tennis dress and with her phone buzzing rapidly in the background.
Her imminent return has been touted since it was revealed in December she had re-entered the anti-doping programme - a prerequisite to play on the tour again.
The American has been given a wildcard for the women's doubles at Queen's, reportedly alongside young Canadian Victoria Mboko.
"Queen's Club feels like the perfect place to begin this next chapter," said Williams.
"Grass has given me some of the most meaningful moments of my career, and I'm excited to be back competing on one of the sport's most iconic stages."
The women's event at Queen's starts on June 8.
"Serena Williams is one of the greatest athletes the world has ever seen, and we're delighted that she will be making her return to tennis at the LTA's HSBC Championships," said WTA tournament director Laura Robson.
"Women's tennis made a historic return to the Queen's Club last year, and now we have an icon of the game stepping back on to court."
Williams said in 2022 she did not want to use the word "retiring" but instead explained she was "evolving" away from tennis.
The American's 23 Grand Slam singles titles are the most by a woman in the Open era and put her second on the all-time list in the women's behind Australian Margaret Court's tally of 24.