Sonic the Hedgehog

Sonic the Hedgehog is the main protagonist of Sonic the Hedgehog series.

Dr. Ivo "Eggman" Robotnik
Dr. Eggman is Sonic's arch-enemy.

Miles "Tails" Prower
Tails is Sonic's fan, mentee, best friend and son figure.

Amy Rose
Amy is Sonic's girlfriend.

Metal Sonic
Metal Sonic is Sonic's robotic copy and second arch-enemy.

Knuckles the Echidna
Knuckles is Sonic's best friend after Tails.

Shadow the Hedgehog
Shadow is Sonic's arch-rival and ally.

Cream the Rabbit
Cream is basically like an younger sister to Sonic.

Blaze the Cat
Blaze is Sonic's close friend and partner in combat.

Silver the Hedgehog
Silver is Sonic's friend and rival.

Chip
Chip is Sonic's close friend.

Jet the Hawk
Jet is Sonic's rival.

Deadly Six
The Deadly Six are Sonic's enemies.

Infinite
Infinite is Sonic's enemy.

Avatar
Avatar is Sonic's close friend and partner.

Allies

 * Team Sonic - Teammates and Closest Friends
 * Miles "Tails" Prower - Fan, Mentee, Partner, Rescuee, Savior, Teammate, Best Friend and Son Figure
 * Knuckles the Echidna - Close Friend, Teammate and Rival
 * Team Rose
 * Amy Rose - Love Interest turned Rescuee and Girlfriend
 * Cream the Rabbit - Rescuee, Close Friend and Younger Sister Figure
 * Cheese the Chao - Close Friend and Rescuee
 * Chocola the Chao - Friend
 * Big the Cat - Friend
 * Froggy - Friend
 * Team Dark - Allies and Former Enemies
 * Shadow the Hedgehog - Arch Rival, Ally and Savior
 * Rouge the Bat - Close Friend
 * E-123 Omega
 * Team Chaotix
 * Vector the Crocodile - Friend
 * Espio the Chameleon - Friend
 * Charmy Bee - Fan and Friend
 * Mighty the Armadillo - Rescuee and Close Friend
 * Ray the Flying Squirrel - Rescuee and Close Friend
 * Tikal the Echidna - Friend
 * Chaos - Enemy turned Friend
 * Lumina Flowlight - Friend
 * Void - Enemy turned Friend
 * Blaze the Cat - Close Friend and Partner
 * Coconut Crew
 * Daikun
 * Colonel
 * Kylok
 * Muzy
 * Setter
 * Tabby
 * Marine the Raccoon - Close Friend
 * Silver the Hedgehog - Close Friend, Rival, Savior and Rescuee
 * Emerl - Rescuee and Friend
 * Vanilla the Rabbit - Rescuee and Friend
 * The President - Friend
 * Guardian Units of Nations - Allies and Former Enemies
 * The Commander
 * Princess Elise - Rescuee and Resurrector
 * Shahra - Friend
 * Caliburn - Friend
 * Merlina the Wizard - Friend
 * Shade the Echidna - Friend and Former Enemy
 * Professor Pickle - Friend
 * Chip - Close Friend
 * Wisps
 * Yacker - Friend
 * Classic Sonic
 * Classic Tails
 * Classic Knuckles
 * Classic Amy
 * Classic Mighty
 * Classic Ray
 * Avatar - Fan, Close Friend, Partner and Savior

Rivals

 * Shadow the Hedgehog - Arch Rival, Ally and Savior
 * Knuckles the Echidna - Close Friend, Teammate and Rival
 * Silver the Hedgehog - Close Friend, Rival, Savior and Rescuee
 * Jet the Hawk
 * Metal Sonic - Robotic Copy, Sworn Enemy and Rival
 * Johnny - Enemy and Rival

Enemies

 * Eggman Empire
 * Dr. Ivo "Eggman" Robotnik - Arch Enemy
 * Orbot
 * Cubot
 * Metal Sonic - Robotic Copy, Sworn Enemy and Rival
 * Nack the Weasel
 * Biolizard
 * Dr. Eggman Nega
 * Pirates
 * Captain Whisker
 * Johnny - Enemy and Rival
 * Mini & Mum
 * Black Arms
 * Black Doom
 * Iblis Trigger
 * Mephiles the Dark - Killer
 * Solaris
 * Ifrit
 * Erazor Djinn
 * Nocturnus Clan
 * Imperator Ix
 * Dark Gaia
 * King Arthur
 * Classic Eggman
 * Time Eater
 * Deadly Six
 * Zavok
 * Zazz
 * Zeena
 * Master Zik
 * Zomom
 * Zor
 * Infinite