Chris Thorndyke (Suzanne Goldish) was the first person Sonic met after coming to the human world. He's the son of a billionaire and movie star and is often alone because his parents are away on business often. He immediately becomes attached to Sonic and tries to help him get home, overcoming his own personal struggles along the way.
Chris' Grandfather Chuck (Jerry Lobozzo) is one of the first people aside from Chris to learn of Sonic and friends. He is an inventor (I don't know why Sonic TV shows are so obsessed with naming their old inventors Chuck) and often would help Tails when fixing up the Tornado.
Ella (Mike Pollock, I'm not joking) was the maid/cook for Chris' family. She helped take care of Chris as well as Sonic and friends.
Mr. Tanaka (Darren Dunstan) was Chris' families butler. He was extremely formal and concerned for Chris' well being when going on missions with Sonic. He is also skilled in martial arts and would teach them to Chris between Season 2 and 3.
Sam Speed (Frank Frankson) was Chris' Uncle who worked on the Station Square Police Force's Speed Team, a unit of the police that would use Formula-1 racecars as vehicles. He was the one sent to capture Sonic after the hedgehog first arrived in the human world, they quickly developed a rivalry where Sam would try to use his racing skills to one-up Sonic.
The President (Ted Lewis) is well the President and spends the beginning parts of the series gathering information on Sonic's Team and Dr. Eggman. He was well meaning but also very fearful and desperate for voters, this leads to him opposing Sonic and friends as often as he helped them.
Topaz (Kayzie Rogers) is a member of G.U.N. and was the first to confront Rogue after she came to the human world and charged with her care. While initially annoyed by Rogue's thievery and greed the two would form a close friendship and eventually become partners in G.U.N.'s ranks. She and Rogue would serve as an envoy between Sonic's Team and the government.
Mr. Stewart (Andrew Rannells) is an agent for the government sent to spy on Chris and Sonic. He replaced Chris' homeroom teacher and would often try to worm his way into uncovering what Sonic and friends were up to. He would eventually aid the heroes once it was made clear that they meant no harm.
(From Left to Right) Bokkun, Decoe, and Bocoe (Bokkun and Decoe voice by Andrew Rannells and Bocoe voiced by Darren Dunstan) were Eggman's lackies for this series. Bokkun was a childish robot who would deliver messages with bombs to Sonic and Friends to gloat and tell them his latest plans. Decoe and Bocoe were his general put upon lackeys similar to Scratch and Grounder before them.