Cavallari, 25, is engaged to Chicago Bears quarterback Jay Cutler, 29.
"We are thrilled to welcome Camden Jack Cutler into the world," Cavallari tweeted. "He was born this morning weighing 7 lbs., 9 oz. Everyone is doing great!"
Cavallari is best known for her work on TV's "Dancing with the Stars" and "Laguna Beach."
Swim Week Miami Beach 2014 [PHOTOS]