The reality star gave birth to her first child with fiancé Roger Mathews on Sunday, 13 July, and named the tot Meilani Alexandra Mathews.
Taking to Instagram on Monday (14 July), the star, 28, said: "My baby girl, Meilani, arrived yesterday and she is perfect!!! Thank you all for your beautiful messages and best wishes, it means the world to me and my family!!"
Jwoww announced her pregnancy on Christmas Day, saying she couldn't wait to start a family with Roger, who appeared alongside her on Jersey Shore.
The couple had become engaged earlier that year when Roger proposed during a skydiving excursion.
Roger has also been on social media sharing his excitement at the new arrival. He tweeted yesterday: "She is here! Meilani Alexandra Mathews 7lbs 13 ounces. Words can't describe what looking into your child's eyes can do to you. I'm humbled.
"She makes cooing noises while she sleeps. Amazing how a simple little noise can make you want to make the world a better place for her 2 live."
Jwoww was congratulated by her Jersey Shore co-stars including best friend Nicole 'Snooki' Polizzi, who is expecting a baby girl of her own later this year.
Got an iPad or iPhone? Reveal Mag is specially designed to fit!
More stars who welcomed babies in 2014:
Copyright: Rex Features WENN/Matthew Taylor/Daniel Deme/Josiah True/Matthre Taylor/Joe