The couple announced the birth of their first child on social media on Sunday.
In October, Teigen spoke publicly about the couple's fertility struggle and how she had undergone IVF treatment to conceive their daughter.
She also revealed that she and her husband had chosen to have a baby girl.
Teigen posted a photo on Instagram showing Luna's weight which was 6lb 11oz and wrote: "She's here! Luna Simone Stephens, we are so in love with you! And sleepy. Very sleepy."
She then tweeted: "To everyone asking, John is healing perfectly."
Before adding: "Thank you for all the well wishes!!! we are so happy and excited! i dunno what to tweet now. does my twitter change? this is so awkward."
The 37-year-old R&B star and the 30-year-old model married in 2013.