Fallon, 40 and his wife, 47-year-old producer Nancy Juvonen welcomed baby daughter Frances Cole Fallon early Wednesday.
"Frances Cole Fallon officially entered the world at 8:45 AM on December 3rd weighing 5 lbs. 11 ounces and is 18.5 inches long," the couple's spokesperson confirms to ET.
Frances Cole joins big sister Winnie Rose, 1.
Just like with Winnie's birth, the couple decided to keep the news private until after Frances' birth. Both Frances and Winnie were born via surrogate.
In August 2013, Fallon shared on Today, "My wife and I had been trying for a while to have a baby. We tried a bunch of things. So we had a surrogate."
Jimmy and Nancy married in 2007.
Congrats to the happy parents!