Sonic the Hedgehog is a blue, 15-year-old hedgehog who lives on the planet Earth. He has the ability to run at supersonic speeds, hence his name. He is always running all over the world, rarely stopping for anything. He is carefree and relaxed; however, he is also very intolerant of injustice, and he will do anything he can to help those in need. He also has a quick wit, a short temper, and a fairly large ego.

Mighty the Armadillo is a 16-year-old red and black armadillo who has a strong sense of justice. Opposed to any and all inhumanity, he uses his power to control the elements - Water, Fire, and Electricity - in his battle against Eggman. He enjoys nature, tranquility, and hot springs.

Shadow the Hedgehog is the "ultimate life form", created in an experiment by Professor Gerald Robotnik aboard the Space Colony ARK. His exact age isn't known, but he is assumed to be around 50 years old. Once hungry for revenge after the death of Maria, Gerald's granddaughter, he is now aware of his past, and who he "is." He prefers to be a loner, but he occasionally tags along with Sonic and his friends when Eggman is up to no good. He uses his ability, Chaos Control, to harness the powers of the Chaos Emeralds to enhance his natural abilities. While he is unable to move very quickly on his own, he possesses fire-powered jet skates, which allow him to move much faster than he can without them.

Miles "Tails" Prower is Sonic's faithful eight-year-old sidekick. Although best known for his two tails, which enable him to fly like a helicopter and give him his nickname, Miles is very intelligent; one could say he is a mechanical genius!

Knuckles the Echidna, named after his fists, is a 16-year-old echidna known for his red-hot temper. An inhabitant of Angel Island, and the guardian of the Master Emerald, he is well known for his brute strength and gullibility.