No, it's not Blair. Or Summer, for that matter.
It's a mini-Blair Waldorf!
Leighton Meester and Adam Brody managed to keep their daughter's birth a secret for more than seven weeks, but now we know that their little girl was born on Aug. 4 -- and her name is adorably old school.
NEWS: Leighton & Adam Welcome First Child
The former Gossip Girl and The O.C. stars given their daughter the moniker Arlo Day Brody. She was born at Whittier Hospital Medical Center, about 24 miles southeast of the couple's home base in Los Angeles.
Don't mind us, we'll just be here picturing all of the cute headbands that will adorn the offspring of a gossip girl.
WATCH: Leighton Reveals Worst Dating Experience Before Marrying Adam
The notoriously private couple first met when they co-starred in 2011's The Oranges and wed in February 2014. This is the first child for both.
Congratulations to the proud parents!