Serena Williams is now the mother of two girls.
Williams' husband, Alexis Ohanian, announced on Instagram that the tennis superstar gave birth to a "happy & healthy newborn girl."
Ohanian shared a picture of himself, Williams, their daughter Olympia and their newborn, Adira River.
In the picture's caption, Ohanian thanked Williams for giving him another "incomparable gift," calling her the GMOAT, or greatest mother of all time.
Williams announced she was pregnant in May at the Met Gala. In late July, she posted a video of her elaborate gender reveal party. Drones spelled out the words, "It's a GIRL."
The announcement came nearly a year after the sports icon said she was "evolving away" from tennis.
Williams played her final match at the U.S. Open in September 2022. She said at the time that she wanted to explore other opportunities in life and expand her family.
Williams will go down as one of the greatest tennis players of all time. In her decades-long career, she amassed 23 grand slam titles, more than any other woman in the Open era.