We all know youthful appearances are pretty much a requirement in Hollywood, but these stars take it to a whole new level. How are they 40 and over?!
In honor of Jennifer Lopez -- who recently Instagrammed a picture of herself in a bikini (and she's killin' it) -- we've rounded up other stars who you won't believe are 40 and over.
Read more: Ageless & A-List stars: Hotter now or then?