The tennis pro, who is due to give birth to her first child in September, posed for photos taken by famed celebrity photographer Annie Leibovitz.
According to reports, Williams' exclusive interview details secrets of her mysterious relationship with fiancé Alexis Ohanian, 33, the co-founder of Reddit.
As RadarOnline.com previously reported, the 35-year-old's sister Venus accidentally revealed that Serena is expecting a baby daughter.
Earlier this month, after her second-round victory in the French Open, Venus, 36, was asked what the baby would call her. "She's going to call me 'favorite aunt'" Venus answered. "Every day we're like, Baby Vee, Baby Isher, Baby Lyn, so we all want the baby to be named after us."
The next morning, Serena was quick to shoot down the slip-up, insisting it was not the big reveal fans assumed.
"I think the surprise of knowing what you are going to have on that very special day you give birth is prob the best surprise you can ever have," Serena posted on Twitter. "So to clarify what Venus said, I am always joking with my sisters to see what favors I can get them to do for me next."
"I did not grow up with any brothers, only sisters and we all say 'she' more than 'he.' Unless I'm joking with my Dad or Alexis and I'm trying to con something out of them too. Hey I'm the youngest of 5 I've always tricked all of them what can I say!" she joked.
Of course, Williams' pregnancy was announced accidentally as well after the star unknowingly posted a baby bump mirror selfie to her Snapchat story.
We pay for juicy info! Do you have a story for RadarOnline.com? Email us at firstname.lastname@example.org, or call us at (866) ON-RADAR (667-2327) any time, day or night.