"I'm the father of a beautiful baby girl. Her name is Winnie Rose Fallon and she's so cute. She's 5 lbs., 9 oz. Me and my wife are so happy," Fallon said during his monologue Wednesday. "Thank you all for all the well-wishes on Facebook and Twitter and the blogs. I'm just so happy."
The Late Night host, 38, and wife Nancy Juvonen Fallon welcomed a baby girl on Tuesday, July 23 at 6:21 a.m., his rep confirms to PEOPLE exclusively.
The first-time parents are "overjoyed about the arrival of their beautiful daughter," the rep tells PEOPLE.
Fallon, who will take over The Tonight Show from Jay Leno next year, and his producer wife, 46, were married in December 2007.