"Saylor James Cutler was born today at 132pm!" she captioned a pic of a pink bow and pink Little Me footie ensemble. Little Saylor weighed in at 7 pounds, 6 ounces.
The Laguna Beach alum, 28, announced in May that she was expecting her third child. In July, she revealed on her app that a baby girl was on the way. "Our new addition!" she captioned a photo of herself embracing Cutler — and holding tiny pink sneakers. "The boys are so excited to have a little sister on the way!!!"
Cavallari and the Chicago Bears quarterback, 32, tied the knot in Nashville in June 2013, and are already parents to sons Camden, 2, and Jaxon, 18 months. In September, the former MTV star told Us about her third pregnancy.
"I'm feeling great! I'm lucky because all three pregnancies have been relatively easy and they've all been the same," she said at the Chinese Laundry NYFW Presentation in NYC at the time. "The only thing is with the girl I feel like I'm carrying a little bit higher, which is kind of interesting. And they do say you carry differently with a girl. So maybe that is true."
She added: "The boys are really excited about having a sister."
Cavallari also gushed about Cutler's parenting skills. "He helps out cleaning up the kitchen. Or he'll make dinner if I want. And he helps out with the boys every night! He's a very hands-on dad, and that's all I could ask for."
Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics, and more delivered straight to your inbox!