| Kay Panabaker | Jenny Garrison |
| Naturi Naughton | Denise Dupree |
| Kherington Payne | Alice Ellerton |
| Megan Mullally | Ms. Fran Rowan |
| Bebe Neuwirth | Ms. Kraft |
| Debbie Allen | Ms. Angela Simms |
| Asher Book | Marco |
| Cody Longo | Andy Matthews |
| Walter Perez | Victor Taveras |
| Charles S. Dutton | Mr. James Dowd |
| Kelsey Grammer | Mr. Martin Cranston |
| Collins Pennie | Malik Washburn |
| Anna Maria Perez de Tagle | Joy |
| Paul McGill | Kevin Barrett |
| Paul Iacono | Neil Baczynsky |
| Kristy Flores | Rosie Martinez |
| Julius Tennon | Denise's Dad |
| April Grace | Denise's Mom |
| Michael Hyatt | Malik's Mom |
| Laura Johnson | Alice's Mom |
| James Read | Alice's Dad |
| Ryan Surratt | Eddie |
| Howard Gutman | Neil's Dad |
| Dale Godboldo | Music Executive |
| J.T. Horenstein | Dance Teacher |
| Stephanie Mace | Mr. Cranston's Assistant |
| Patrick Censoplano | Brooklyn Boy |
| Donnie 'Burger' Winston | Hype Man |
| Marcus Hopson | Senior Rapper |
| Krystle 'Ak'sent' Johnson | Female Rapper |
| Tynisha Keli | Female Singer |
| Kate Mulligan | Karaoke Singer |
| Don Smith | Film Set PA (as Donnie Smith) |
| Earl Carroll | Camera Shop Clerk |
| Oren Waters | Singing Homeless Man |
| Tim Jo | Korean Boy |
| Michael Eric Reid | Red Haired Boy (as Mikey Reid) |
| Leslie Ishii | Administrator |
| Gavin Turek | Ethnic Girl |
| Paulina Gretzky | Gorgeous Blonde Senior |
| Alex Liddy | Friend of Brooklyn Boy |
| Bre Morgan | Intense Girl |
| Anastasia Boissier | Little 10 Year Old Girl |
| Kasha Kropinski | Ballerina |
| Jessie Sherman | Drama Helper |
| Jeremy Hudson | Dancer Boy |
| Mallauri Esquibel | Dancer Girl |
| Annika Daniel | Marco's Little Sister |
| Sophia Daniel | Marco's Little Sister |
| Tiffany Espensen | Joy's Sister |
| Scott J. Wood | Teacher (as Scott Wood) |
| Eli Myers | Cafeteria Jam Piano Student |
| Seth Daly | Cafeteria Jam Violin Student |
| Miss Lola Rose | Butcher Shop Customer |
| Nisha Bedi | Drama Student #1 |
| Nick Grimes | Drama Student #2 |
| Angela Alexander | Drama Student #3 |
| Eva Ramirez | Drama Student #4 |
| Whitney Barncord | Drama Student #5 |
| Brittany Magill | Drama Student #6 |
| Smyth Campbell | Drama Student #7 |
| Gino Barletta | Drama Student #8 |
| Philomena Bankston | Drama Student #9 |
| Ronald Kartoon Antwine | Nightclub Bouncer |
| Sharon Pierre-Louis | Broadway Girl |
| Hailey Villaire | Opera Girl |
| Deanna Knott | Club Jam Vocal #1 |
| Krys Ivory | Club Jam Vocal #2 |
| Betty Griffin-Keller | Orchestra Conductor |
| Luoc Lee | Karaoke Server |
| Dani Miura | Gospel Singer / Student |
| Don Abernathy | Audience Member / Teacher (uncredited) |
| Lisette Alvarez | Ballerina (uncredited) |
| Deanne Destler | Drama Student (uncredited) |
| Krystal Ellsworth | Featured Dancer (uncredited) |
| Mark Anthony Lopez | Club Patron (uncredited) |
| Katrina Norman | Dancer (uncredited) |
| Paul Peglar | Student with Glasses (uncredited) |
| Allie Rivera | Gospel Choir (uncredited) |
