At the Met Gala on Monday, the four-time Olympic champion revealed the big news while she appeared on the red carpet alongside her husband Alexis Ohanian.
“There are three of us here,” the legendary tennis player gushed during an interview, pointing to her stomach.
Twitter users were quick to respond to the news, sharing their excitement at the star athlete who is expecting her second child.
Williams and Ohanian welcomed their first child, Alexis Olympia Ohanian Jr., in September 2017.