Posting a photo of the newborn on Twitter, she wrote: “And just like that, our hearts exploded into all of eternity and beyond. Welcome to the world you little angel!”
Dewan is already mother to six-year-old daughter Everly, who she shares with her ex-husband Channing Tatum.
She was married to Tatum for nearly nine years before they publicly separated in April 2018.
Broadway star Kazee posted another photo of the child on Instagram, writing: “In an instant our universe burst wide open and nothing would ever be the same. Welcome to earth star child.”
Dewan, 39, and Kazee, 44, announced they were expecting their first child in September.
She shared a message in which she said they had “a lifetime to love and grow” together.
Jenna Dewan shares baby news with fiance Steve Kazee
