Sean Marquette
Travis Breaux
Michael Chiklis
Dr. Leslie Gordon
Adhir Kalyan
Sebastian Saleem
Mykelti Williamson
Paranoid
Alicia Sixtos
Sharky Ovante
Erica Vittina Phillips
Tameka
Arcadiy Golubovich
Edwin Hunter
Yeardley Smith
Computer Skills Teacher
Curtis Armstrong
Mr. Thompson
Alex Biats
Spelling Bee Rival
John Beard
Male News Desk Reporter
Barret Swatek
Female News Desk Reporter
Wyatt Russell
Drug PSA Stoned Teenager
Heather Elizabeth Regan
Cheerleader who collides with Henry
Terri Lyn Rodriguez
Vivian
Shirley Benyas
Older Female Donor
Wallace Bridges
African American Donor
Carl Harry Carlson
Donor #1
Nadine Crocker
Emily Tooms
Clarence Smith
Chess Opponent
Ron Ayers
Stunned Lawn Bowler
Rachel Quaintance
Angry Parent #1
Peter Tocco
Angry Parent #2
Kerry Birmingham
Female Reporter
David Herbst
School Security Guard
John O'Hurley
Drug PSA (voice)
John Stalberg Jr.
Grandpa Frodo - Ed's Frog (voice)
Heather Kleisner
Henry's Mom (voice)
D.B. Dickerson
Stoned High School Student (uncredited)
Sabrina Dungan
High School Student (uncredited)
Penny Gibbs
School Admin (uncredited)
Adam Lorenz
Dwayne Reynolds (uncredited)
Bill Lumbert
Concerned Parent (uncredited)
Misty Mills
Teacher (uncredited)
Jerry Reid
High School Student (uncredited)
Steven Sutherland
Academy Student (uncredited)
Joe Tinpan
Terrorist (uncredited)
Michael Vartan
Calculus Teacher (uncredited)
Amanda Bright
High School Student (uncredited)