Marnie puts her magic on the line to get several Halloweentown teenagers transferred to her high school in the mortal world. But soon, Marnie and her new friends are in trouble and out of luck when the evil Knight Of The Iron Dagger appears. He's determined to destroy all things magical, and it's up to Marnie to save her high school, the human world and her magic.
| Actor | Role |
|---|---|
 Kimberly J. BrownMarnie Piper | Marnie Piper |
 Debbie ReynoldsAggie Cromwell | Aggie Cromwell |
 Judith HoagGwen Piper | Gwen Piper |
 Joey ZimmermanDylan Piper | Dylan Piper |
 Emily RoeskeSophie Piper | Sophie Piper |
 Finn WittrockCody | Cody |
 Clifton DavisPrincipal Flannigan | Principal Flannigan |
 Eliana ReyesCassie | Cassie |
 Lucas GrabeelEthan | Ethan |
 Michael FlynnDalloway | Dalloway |
 Olesya RulinNatalie | Natalie |
| TTodd Michael SchwartzmanPete | Pete |
| CClayton TaylorLittle Chester | Little Chester |
| JJesse HarwardBig Chester | Big Chester |
| JJeff OlsonSix Armed Man | Six Armed Man |
 Frank GerrishPumpkinhead | Pumpkinhead |
 Mowava PryorVampire | Vampire |
 Darin ScottTroublemaker | Troublemaker |
| HHaley McCormickGirl #1 | Girl #1 |
| MMark ReedTV Newscaster | TV Newscaster |
| MMichelle BrinkerhoffStudent #1 | Student #1 |
| HHolly AldermanStudent #2 | Student #2 |
| BBrooke AldermanStudent #3 | Student #3 |
 Carleton BlufordStudent #4 | Student #4 |
| KKristin AlaynaStudent #5 | Student #5 |
| JJohn ColosimoCoach | Coach |
 Frank WelkerPurse Monster (voice) (uncredited) | Purse Monster (voice) (uncredited) |