The "Single Ladies" hitmaker announced the news in an Instagram post on Wednesday with a picture showing her cradling a baby bump, the Guardian reported.
The post read: "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 announcement had more than 1.5m "likes" within 35 minutes of publishing. Beyoncé, 35, has a five-year-old daughter named Blue Ivy with husband rapper Jay Z. She revealed her pregnancy with Blue Ivy on the red carpet at the MTV music awards in 2011, after finishing her performance.