Keys, who is 29, is expecting her first child with her fiancé, producer Swizz Beatz. He's written hits for Beyonce, Jay-Z and others.
Reps for the couple confirmed the news Thursday night.
Keys last year teamed up with Jay-Z for a hit song about New York called "Empire State of Mind." She's among a string of international artists slated to perform at a June 10 concert to mark the start of the World Cup soccer tournament in South Africa.
Beatz has been married before and has two sons.
The Associated Press contributed to this report.