Cameron Diaz, Gwyneth Paltrow, Ben Affleck and more! See the seemingly ageless A-listers celebrating 40th birthdays this year
Jude Law (December 29)
The British actor (seen here in 1999) says he's never felt more confident. "I feel more and more at ease, because . . . the older I get, the less pressure there is," Law explained to GQ UK recently.