- Cymphonique Miller as Kacey Simon, the lead singer and guitarist of the band "Gravity 5".
- Noah Crawford as Stevie Baskara, the drummer of the band.
- Lulu Antariksa as Nelson Baxter, the keyboardist and backup vocalist.
- Chris O'Neal as Andy Bartlet, the bassist and vocalist.
- Samantha Boscarino as Molly Garfunkel, Kacey's best friend and the band's manager.
- Hal Sparks as Principal Horace P. Hedd, the principal of Hamilton Middle School.
- Max Schneider as Zander Robbins, a popular student who is Kacey's love interest.
- Anna Camp as Macy McHenry, a music industry executive and mentor to Kacey and the band.