Oz in 'American Pie' Movies 'Memba Him?!

Illinois-born actor Chris Klein was 20 years old when he landed the life-changing role of hunky high schooler Chris "Oz" Ostreicher -- who leaves his lacrosse team hanging to join the choir for the cute girl -- in the OG teen film "American Pie" ... and the follow-up films "American Pie 2" and "American Reunion."

Chris Klein shared the big screen with young actors on the rise including Mena Suvari as the sing-songy GF, Heather, Shannon Elizabeth as the foreign exchange hottie, Nadia, Natasha Lyonne as the jaded classmate, Jessica ... and of course Jason Biggs as the pie-loving, Jim.