Glee cast and college (all info from Wikipedia):

Jacob Artist: was accepted into Julliard for dance but turned it down to pursue acting

Melissa Benoist: graduated from Marymount Manhattan College

Chris Colfer: attended community college briefly before booking Glee

Darren Criss: graduated from University of Michigan (majoring in theater performance and minoring in musicology and Italian)

Jessalyn Gilsig: graduated from McHill University with a BA in English and also studied at Harvard’s Institute for Advanced Theater Training

Dot Marie Jones: attended Modesto Junior College and Fresno State

Jane Lynch: graduated Illinois State University with a BA in theater and a MFA in theater from Cornell University

Jayma Mays: AA from Southwest Virginia Community College, attended Virginia Tech for a year and transferred to Radford University

Lea Michele: was accepted to NYU’s Tisch School of the Arts but opted to work professionally as an actress

Heather Morris: enrolled in a local university but dropped out to pursue dance/move to LA

Matthew Morrison: attended NYU’s Tisch School of the Arts for two years but dropped out to join the Broadway adaptation of Footloose

Alex Newell: was accepted into the Berklee College of Music but turned it down to move to LA/be on Glee

Mike O'Malley: graduated from University of New Hampshire where he studied theater

Mark Salling: attended Los Angeles Music Academy College of Music where he studied guitar

Becca Tobin: graduated from American Musical and Dramatic Academy

Jenna Ushkowitz: graduated from Marymount Manhattan College with a BA in theater arts and a concentration in performance and a minor in musical theater

Ryan Murphy: graduated from Indiana University, Bloomington

Brad Falchuk: graduated from Hobart and William Smith Colleges and American Film Institute

Ian Brennan: studied theater at Loyola University Chicago and also studied at The Second City Training Center