By InStyle Staff
Apr 29, 2012 @ 11:00 am
Yearbook Library; Globe

Can you guess who these birthday girls are by looking at their pre-fame shots? Uma Thurman (top) is celebrating her 42nd birthday today, while Michelle Pfeiffer turns 54. Congratulations, ladies! Click through our gallery to see Michelle's Hollywood transformation, from flaxen-haired teen to big screen siren. 

MORE:See Uma Thurman's Transformation, Too!Uma's Big Marilyn Monroe Reveal on SmashMichelle Pfeiffer: Then and Now