The pop superstar Mariah Carey gave birth to a boy and a girl at an undisclosed hospital in Los Angeles on the date of the couple's fourth wedding anniversary.
The baby girl was born first, weighing in at five pounds, three ounces (2.4 kilograms), while her brother followed, weighing five pounds, six ounces (2.5 kilograms).
Soon after news of the birth broke, the couple's famous friends flooded Twitter with congratulatory messages.
Hip-hop star Nicki Minaj wrote, "Congratulations Mariah & Nick! The twins have finally landed on earth! Yaaayyyyy!," while Alyssa Milano sent the couple a message saying, "Congrats!"
Mariah Carey's "One Sweet Day" collaborators, Boyz II Men, wrote, "Just got the news! Congrats Mr and Mrs Nick Cannon on ur (your) twin babies!! Look forward to sleepless nights for the next few weeks..." while music producers Jermaine Dupri and Rodney Jerkins also sent their best wishes.