The 'My Heart Will Go On' hitmaker delivered the babies via Caesarean section at St Mary's Medical Centre, in West Palm Beach, Florida.
Although the 42-year-old singer and the babies are said to be doing well, the tots will spend the next few days in incubators as they were born prematurely, Contactmusic reported.
Dion also has a nine-year-old son named Rene-Charles with husband Rene Angelil.
"Celine is resting now and they plan to discuss what to name the boys when she wakes up. Rene-Charles has been to the hospital to visit his brothers and is just so excited they are here," a representative for the couple said.
The Canadian singer, who suffered a miscarriage in 2009, underwent six gruelling courses of IVF to get pregnant again. The process left her mentally exhausted.
"I feel like I've been pregnant for over a year. I never gave up. But I can tell you that it was physically and mentally exhausting," Dion said.