Mary-Kate Olsen, Ashley OlsenWarner Bros/Everett Collection; Larry Busacca/Getty Images

Double up the birthday cake—Mary-Kate and Ashley Olsen turn 26 today! To celebrate, we’re taking a look back at the twins’ Hollywood transformations, from Full House babies to award-winning fashion designers. See their evolution in the galleries!

SEE MARY-KATE TRANSFORM

SEE ASHLEY TRANSFORM

MORE:
Mary-Kate and Ashley Win at the CFDA Awards
Celebrity Bikinis 2012: Ashley Olsen
Preview the Olsens’ Fall Collection for The Row