It's not surprising that the couple was able to keep the birth under wraps for two weeks, as they also secretly tied the knot in Big Sur, California, in 2012, and Hathaway's baby shower back in March was equally low-key.
"Posting a bikini pic is a little out of character for me, but just now while I was at the beach I noticed I was being photographed," she wrote on Instagram. "I figure if this kind of photo is going to be out in the world it should at least be an image that makes me happy."
Before giving birth, Hathaway snapped a shot of her bump alongside her Academy Award. Check the photo out in the video below.