Reynolds, 47, announced the name while speaking at the Deadpool & Wolverine premiere at Lincoln Center in New York City.
“I want to start by saying thank you to my wife Blake, who is here,” he shared from the stage.
He added: “I love that my entire family is here.”
Reynolds and Lively, 36 — who also share daughters James, 9, Inez, 7, and Betty, 4 — seemingly confirmed the birth of baby No. 4 in February 2023
five months after Us Weekly confirmed that Lively was pregnant. At the time, the Gossip Girl alum appeared without a baby bump in a carousel of images she shared via Instagram.
Two months later, Lively stepped out for her first post-pregnancy red carpet while attending Barnard College’s Annual Gala in New York City.
However, while fans speculated she and her spouse would make an appearance at the 2023 Met Gala in May
“You will not [see me there]. But I will be watching,” Lively shared at the Tiffany & Co. store opening in April, joking that she would be donning her 2022 Versace gown to watch the soirée “on my couch.”