A 13 year old boy named Corey Riffin starts a garage band with his friends Kin, Kon, and Laney and quickly comes to the realization that his band sucks. It's not their music or ever changing image that's the problem. It's their lack of good lyrics. Corey and his band was great at everything else that's needed for making a band, but they just could'nt think of any lyrics. This was all until they found Corey's older sister Trina's diary. When they looked in her diary they found that her entries were so profound that they would make perfect lyrics for songs. All they need to do is toy with her emotions to make her write in her diary about her problems and angst so that they can put her diary entries into lyrics. Follow Corey and his Grojband as they reach for the top and go on wild adventures to try and anger Trina and get lyrics for a new song before they go up on stage and play their next gig. Gasp at the problems they face and the solutions they come up with to get their band noticed and Grojband can be the biggest band in all of Peaceville.
- Corey Riffin - Corey is the main character and protagonist of Grojband. He is a cute, quirky, 13 year old boy as well as the lead singer and guitarist of a garage band with his friends called Grojband. He is the one who takes his band mates on their daily wild adventures to get lyrics for their next song. Corey has A.D.D. and O.C.D. which causes him to obsess over playing gigs at whatever chance he gets and for him to never be able to hold still and always be bent on doing something out of this world. This may come on as a burden at times but it is also what helps him be a great rock star and to make his band awesome and for him to be a good friend. He is voiced by Lyon Smith.
- Kin Kujira - Kin is one of the main protagonists of the show. He is an incredibly intelligent super genius kid who can build many inventions and he is the keyboardist of the band and has a twin brother named Kon. Kin and Kon are the best of friends and they do everything together. He is voiced by Sergio Di Zio.
- Kon Kujira - Kon Kujira is one of the main protagonists of the show. He is Kin's younger twin brother and the drummer of Grojband. Although Kon is fat and stupid and eats a lot, he is a very nice and loving guy. He is voiced by Tim Beresford.
- Laney Penn - Laney is a character on the animated show Grojband. Short in stature, tall in ambition; Laney is the rock of this rock and roll band. This red-haired firecracker is the band’s bassist and self-proclaimed band. Which, in this band, means trying to make Corey’s latest idea come together as planned. She is voiced by Bryn McAuley.
- Trina Riffin - Trina Riffin is the main antagonist in the show. She is the 16 year old older sister of Corey and she is always trying to destroy Grojband because she hates it with a burning passion. She has severe anger issues which helps Grojband write a good song in the end of every episode of Grojband. They enrage her big time and she writes about it in her diary. They get it from her and put her words into lyrics. She is voiced by Alyson Court.
- Mina Beff - Mina Beff is Trina's best friend and lackey. Despite wanting to express her own opinion, she wishes to be as cool as Trina and does whatever she asks her to. She does this so that she can be as popular as Trina and seems to be oblivious to the fact that Trina is not popular at all. She is voiced by Denise Oliver.
- Nick Mallory - Nick Mallory is the coolest kid in the school, whom all the girls in his grade love especially Trina even though eh is oblivious to her existance. He is quite narcissistic and refers to himself in the third person however, he is not antagonistic and is very good of a friend to Corey and will often times aid him and his friends with their band whenever they need him. He is voiced by Graeme Cornies.
- Mayor Mellow - Mayor Mellow is the crazy mayor of Peaceville who mostly talks in rhymes. He serves as some form of a semi-antagonist in the show and is often times coming in the way of Grojband. He fears that Grojband is going to disrupt the peace of his peaceful city Peaceville and is slightly problematic to Grojband trying to play their gigs. He is voiced by Kedar Brown.
- The Newmans - The Newmans are the rival band of Grojband. They are exactly like them only their genders are the opposite. Their band consists of four members. Carrie Beff, the lead singer and guitarist of the band, Kim Kagami, the keyboardist of the band, Konnie Kagami, the drummer of the band, and Lenny Nepp, the bassist of the band. Their main goal is to become bigger than Grojband which they are not right now. They are an evil band and they are always trying cruel things to become bigger than Grojband but they always fail at their schemes. They serve as a major antagonist in the show. They are voiced by Lyon Smith (Carrie), Sergio Di Zio (Kim), Tim Beresford (Konnie), and Bryn McAuley (Lenny).
- Kate and Allie - Kate Persky and Allie Day are groupies of Grojband. They are their biggest fans and they are insanely obsessed with them. They are always following Grojband around like a bunch of creepy stalkers. They are extremely loyal to Grojband and they will always go out of their way to throw themselves into all sorts of danger just to help the band. They are voiced by Addison Holley (Kate) and Madelyn May (Allie).
Main Article: List of Grojband episodes