The actors named their first child Bodhi Soleil Reed Somerhalder.
The baby was born on July 25, People confirmed.
Bodhi is the first child for the couple, who wed in April 2015.
38-year-old Somerhalder and Reed, 29, announced the pregnancy news in May with matching Instagram posts, featuring a serene snap of "The Vampire Diaries" star kissing his wife's growing belly.