Lil Rob (voiced by Rob Dyrdek) - Lil Rob is the titular character and the leader of the Wild Grinders. He is an upbeat per-adolescent with an adventurous personality, and infinitely never surrenders from his rival, Stubford Hucksterball. His aliases include Kid Voltage in "The Amaaazing Adventures of Captain Grindtstar" and Agent Supernova in "Substitute Secret Agent". Rob is the lead singer of the Backside Grinders. Meaty (voiced by Sterling "Steelo" Brim (season 1), Lee Harrell (season 2)) - Lil Rob's anthropomorphic British bulldog. He favors eating burritos, bacon, and especially the extinct Stinkies products. He's also known for being the Backside Grinders drummer, Meat-Borg in "The Amaaazing Adventures of Captain Grindtstar", and Agent MeatBag in "Substitute Secret Agent". In the pilot online episodes, Meaty didn't talk. Goggles (voiced by Yuri Lowenthal, credited as Jimmy Benedict) - Lil Rob's nerdy and loyal friend. He is the cameraman of both the Wild and Backside Grinders and the major inventor, but he can be forgetful of anything that the Grinders want significant. Known as Goggle Lad in "The Amaaazing Adventures of Captain Grindtstar" and Agent Whiz Kid in "Substitute Secret Agent". In the pilots, he rarely spoke but when he did, his voice was deeper. He's also the weakest skater out of the team, confirmed in "Swaggerless", and according to Jack Knife. Emo Crys (voiced by Cam Clarke, Yuri Lowenthal in pilot episodes (uncredited)) - The poetic and sensitive of the Wild Grinders. Emo Crys is frequently a skate artist and creates terrible and dark poetry. He sometimes goes "girl-crazy". Known as cowbell player from the Backside Grinders and Emo Scissor Clippers "The Amaaazing Adventures of Captain Grindtstar". The pilot episodes showed him that he was Lil Rob's best friend instead of Goggles. Jay Jay (voiced by Kel Mitchell) - An intelligent hipster. He was portrayed to have mysophobia. He's the Backside Grinders' keyboard player. In the pilot episodes, Jay Jay in known to be Lil Rob's friend, instead of Goggles. Jack Knife (voiced by Yuri Lowenthal) - A dull kid with a big heart. He and his family runs a circus in Sprawl City. He plays electric guitar in the band which he initially used as a saxophone. In the pilots, Jack Knife didn't have his southern accent. Spitball (voiced by Yuri Lowenthal) - The silent type and dubbed as Street Ninja. He's the Backside bass player. He only spoke Spanish in the pilots. Stubford Hucksterball (voiced by Erin Fitzgerald) - The main antagonist of the entire series. He is a child with a short height, but summons his mechanical stalls to make him taller than the Grinders. He frequently aliases Lil Rob as "Lil Slob". He made no appearances prior to the show's official debut. Flipz (voiced by Chanel West Coast) - The only female skater in the Wild Grinders. She tends to challenge Lil Rob to S.K.A.T.E. in most of her appearances. Although she joins the Grinders, she was not shown at all times.
- Carey Mahoney – The most clever among the cadets. Mahoney is always ready to lend a hand to his companions. He is the patrol partner of Larvell Jones.
- Larvell Jones – Mahoney's usual sidekick. He's a martial arts master, but his main talent is beatboxing – he is able to make every kind of noise (sirens, gunfire, helicopters, etc. ...).
- Carl Sweetchuck – Sweetchuck is the most cowardly of the group. He is very accident prone and oblivious to the harm caused by his clumsiness. His patrol partner is Zed.
- Zed McGlunk – Zed is the messy and unkempt member of the group. Zed usually drags his partner along in his wily and erratic pursuits.
- Moses Hightower – Hightower is known for his great size and physical strength. His stature often comes into play when the characters find themselves in situations in which bars must be bent or walls need to smashed through. He is patrol partner with Laverne Hooks.
- Laverne Hooks – Hooks is small, soft-spoken, and passive. However, she has shown herself capable of being extremely forceful and loud in situations in which she is provoked.
- House Conklin – "House" is known for his large frame and his congenial nature. He is always hungry and proves himself to be cowardly. He patrols with Sweetchuck and Zed and often accompanies them in their escapades.
- Eugene Tackleberry – Characterized by a pronounced jaw almost always wears glasses and helmet, is a weapons fanatic; has a weakness for his fellow patrol Callahan. Often uses the armored car of the police which he usually wrecks. Often uses a bazooka.
- Debbie Callahan – Is the statuesque beauty of the group who is tough-as-nails and has a beautiful singing voice.
- Thaddeus Harris – Always carries a walking stick and is almost always in the company of his sidekick Proctor. Often tries to humiliate the officers in order to gain a promotion.
- Carl Proctor – Is Capt. Harris' idiotic lieutenant.
- Eric Lassard – The easygoing and idealistic commandant.
- Professor – He is the inventor of numerous devices.
- K-9 corps – They are trained dogs. They can talk, but only to themselves and other animals.