The 39-year-old "Hart of Dixie" star took to photo-sharing mobile application Instagram to reveal the name.
"Kyle and I named our second son Leo Thames Newman," she wrote.
Earlier, Newman, who directed Taylor Swift's music video "Style", welcomed the child by sharing the news.
"He's arrived! So happy to welcome our new baby boy into the world. Born July 16th! Mom and Baby are well. Name coming soon.
The "Star Wars: The Clone Wars" actress uploaded a picture of the family.
"We are so happy to welcome to the world our new baby boy!" King captioned the family photo in the hospital.