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?!
"The Voice" judge and No Doubt frontwoman Gwen Stefani turned 45 on Friday, meaning that she's at least 20 years older than she looks!
Also Jennifer Lopez 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?