The hunky new dad couldn't help but tease Today co-host Willie Geist before confirming what was rumored weeks ago.
"It's Butternut Summer Squash," Reynolds, 38, joked. "No, it's out there. It's James. Everyone knows, and I told everyone who would listen before it was out there that I didn't want to be the first guy screaming it out to the media because, as we know, little girls turn into teenage girls and little teenage girls sometimes scan through the archives and go, 'Why did you do that?'"
Indeed, the Woman in Gold actor joked earlier this month that his infant daughter would probably make him pay for blurting out her name. "She will exact her revenge in searing, psychic pain," he told the Associated Press.
In February, he added to David Letterman: "I threw out the idea of just never naming the kid to be totally original, but we have a name. I just don't want to say it in, like, a media context. I tell everyone who I meet, so it'll come out."
Reynolds and Lively, 27, welcomed their first child just before the New Year. Since James' arrival (oh, those good genes!) Reynolds has also cracked that she's "totally average" and seems to be "allergic to sleep." See Blake's first official post-baby red carpet pics.