Before Michael Cera was defeating evil boyfriends in "Scott Pilgrim" or being anxious in "Arrested Development," he was just a whiny kid -- with "very delicate bone structure" -- in a Mary-Kate and Ashley Olsen movie.

Cera's not the only Hollywood star to get his start in an Olsen movie. "Transformers" starlet Megan Fox wasn't always breaking hearts and taking names. In 2001's "Holiday in the Sun" -- Fox's film debut -- the future on-screen vixen was a total mean girl, out to ruin Mary-Kate and Ashley's fun in the sun.

Future "House" star (and Aussie) Jesse Spencer played a handome Brit who romanced Mary-Kate in 2001's "Winning London," while "One Tree Hill" stud Austin Nichols also had his eye on Mary-Kate in "Holiday in the Sun."

Click through the gallery below to see more famous faces in Mary-Kate and Ashley Olsen movies.

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  • Michael Cera in "Switching Goals"

  • Megan Fox in "Holiday in the Sun"

  • Jesse Spencer in "Winning London"

  • Austin Nichols in "Holiday in the Sun"

  • Ethan Peck in "Passport To Paris"

  • Lizzie Olsen in "Adventures of Mary-Kate and Ashley"

  • Troian Bellisario in "Billboard Dad"

  • Kirstie Alley in "It Takes Two"

  • Steve Guttenberg in "It Takes Two"

  • Alison Pill in "You're Invited to Mary-Kate and Ashley's Camp Out Party"

  • Eric McCormack in "Double Double Toil and Trouble"

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