* Mary-Kate Olsen as Amanda Lemmon/Alyssa Callaway
* Ashley Olsen as Alyssa Callaway/Amanda Lemmon
* Steve Guttenberg as Michael Grover
* Kirstie Alley as Diane Barrows
* Diane Wiest as Mrs. Callaway
* Larry Miller as Mr. Lemmon
There are other supporting actors as well, but these are the main cast members.