Zac Efron (Mike O'Donnell (17 years))
Leslie Mann (Scarlet O'Donnell)
Thomas Lennon (Ned Gold)
Matthew Perry (Mike O'Donnell (Adult))
Tyler Steelman (Ned Gold (Teen))
Hunter Parrish (Stan)
Katerina Graham (Jamie)
Tiya Sircar (Samantha)
Melora Hardin (Principal Jane Masterson)
Brian Doyle-Murray (Janitor)
Jim Gaffigan (Coach Murphy)
Mario Cassem (Samir)
Melissa Ordway (Lauren)
Josie Loren (Nicole)
Randy Gordon (Photographer)
Collette Wolfe (Wendy)
Tommy Dewey (Roger)
Allison Miller (Scarlet (Teen))
Sterling Knight (Alex O'Donnell)
Michelle Trachtenberg (Maggie O'Donnell)
Adam Gregory (Dom)