Husband Jay Z and 5-year-old daughter Blue Ivy were spotted at a Los Angeles-area hospital on Thursday.
The exact date of the twins' birth was not immediately known.
Beyoncé used Instagram to reveal her pregnancy. In early February she posted a photo of herself sporting a baby bump while dressed in lingerie and surrounded by flowers.
"We would like to share our love and happiness. We have been blessed two times over. We are incredibly grateful that our family will be growing by two and we thank you for your well wishes. – The Carters," the Instagram caption read.
While Beyoncé's pregnancy led her to cancel her headlining appearance at Coachella in April, she is still set to headline the 2018 festival. She has been spotted courtside at basketball games and at awards shows with her baby bump since the February announcement. Beyoncé had a baby shower, called the "Carter Push Party," in May to celebrate the incoming twins.
Beyoncé and Jay Z welcomed Blue Ivy Carter, the pair's first child, on Jan. 7, 2012. The couple has been married since 2008.