Baby Benjamin was born Tuesday and weighed in at 8 pounds, 3 ounces.
Preston and Travolta are also the parents of a 10-year-old daughter named Ella. Their son Jett died in January 2009 after suffering a seizure. He was 16.
"John, Kelly and their daughter Ella Bleu are ecstatic and very happy about the newest member of the family," representatives for the couple said in a statement issued to People.com Wednesday. "Both mother and baby are healthy and doing beautifully."