Caleb Followill has become a father for the first time.
No further information about the baby has yet been revealed.
The couple announced Lily's pregnancy in December.
Speaking in a statement, the couple said: ''We are thrilled to announce that we are expecting our first child together. We can't wait to meet the new addition to our family.''
The 30-year-old rocker married the Victoria's Secret beauty at San Ysidro Ranch in Montecito, California in May 2011 after dating for more than two years
Lily - who walked down the aisle in a custom-made Vera Wang gown - previously admitted her wedding was perfect and says she wouldn't have changed anything about the sunset ceremony.
She added: ''It was really an amazing day. It was more beautiful than I could've imagined.''