Sonic is the main protagonist of the series. Sonic is 15 years old at the beginning of the series and turns 16 in the middle of the first season. Sonic is at first hesitant in accepting his role as leader of the Hyperforce, but gradually comes to accept his destiny of becoming a defender of Central and later the universe. He falls head-over-heels in love with a female protagonist, Jinmay the robot. He pilots the Torso Tank Driver 1, which forms the torso and limbs of the Super Robot. Sonic's powers come from the Power Primate, an entity inside of him. Not much is known about Sonic's background. He is voiced by Greg Cipes.

Shadow the Hedgehog is the black suit-wearer in the first two seasons of the series. After being resurrected, he becomes the powerful silver suit-wearer in the third and fourth seasons. He is second in command of the Hyperforce. Shadow is wise, serious, calm and collected, and cares very much for his friends. He teaches Sonic how to control the Power Primate and gives spiritual advice to the rest of the Sonic Team. He spends most of his time either defeating demons or patrolling Central City. He pilots the Egg Scrambler 2, which forms the head of the Super Robot. His main weapons are his Ghost Claws in addition to the Chaos Lance, an attack Sonic learns during the series. Sonic adopts Shadow as a father figure and becomes very close to him. Shadow is voiced by Kevin Michael Richardson.

Knuckles the Echidna is the red suit-wearer and the team's best pilot. He is very much the comedian of the group. But, he is still very brave and willing to protect his comrades at any cost. Though he is the very essence of annoying to Marine, he still harbors feelings for her. This doesn't keep him from hitting on other females at times, even right in front of Marine. He never calls Sonic anything but "Kid," except in select episodes. He pilots the Fist Rocket 3, which becomes the right hand of the Super Robot. His main weapons are his Fists. He turned evil in the second-to-last episode Fire of Hate, but with the help of his friends, and a love confession from Rouge, he turns good again in the last episode Soul of Evil. He is voiced by Corey Feldman.

Blast the Badger is the blue suit-wearer, and the team's scientist. His full name is Mr. Gui Blast, but he prefers "just 'EJ'. When answering scientific-related questions, he answers them with long, even confusing and boring, speeches, which are always interrupted by someone or something. He has trouble deciding if Tails, the team's mechanic, is a genius or an idiot. He despises bugs but not someone who is smarter than him. He pilots the Fist Rocket 4, which becomes the left hand of the Super Robot. His main weapon are his Floor Blast and Fire Drills. These contain a variety of different charges within them, giving him the widest choices of attacks. He is voiced by Tom Kenny.

Tails the Fox is the green suit-wearer and the team's mechanic. Although his talent with machines is unmatched, he is quite oblivious to everything else around him. He has an obsession with naming the monsters the team encounters. As the team are animals themselves, it is usually up to Tails to repair any damages. Tails has a dream of being in the circus - more specifically, being a trapeze artist. He also has a soft spot for anything young or smaller than him, as seen in The Stranded Seven when he gives the seemingly useless piece of metal on the end of his tail to a young cat-like alien, whom he called "Lil' guy." He pilots the Foot Crusher Cruiser 5, which becomes the left foot of the Super Robot. His main weapons are his Dummy Ring Bombs. He is voiced by Clancy Brown.

Marine the Raccoon is the yellow suit-wearer with pink eyes, and the only female on the team until Jinmay became an honorary member. She's the team's main fighter and has been known for her fiery attitude. She has a love-hate relationship with Blast. She eventually admits her feelings, claiming she loves him and saying that it's "too much to lose him", in the last episode. She had a loving bond with her creator, the Alchemist, who becomes Skeleton King due to an accident in his lab caused by Mandarin (the original leader of the Monkey team who later became evil), (when he was human, the Alchemist used to call Marine "Dearest Marine.") She also cares for Sonic as if he were a brother of hers. Shadow stated she's the team's third-in-command, which did not bode well with Knuckles and Tails, as they were fighting about who it would be in the episodes The Savage Lands, Part 1 & 2. She pilots the Foot Crusher Cruiser 6, which forms the right foot of the Super Robot. Her main weapon is her telekinesis. She is voiced by Kari Wahlgren.