Sonic the Hedgehog 3
North American box art
Developer(s) Sonic Team
Publisher(s) SEGA
Series Sonic
Designer(s) Hirokazu Yasuhara
Engine Sonic 1 Engine Modified
Genre(s) Platform, Adventure
Platform(s) Sega Mega Drive/Genesis, PC, Mac OS X, Virtual Console, Xbox Live Arcade
Media 8-Megabit cartridge
Input methods Game controller

Sonic the Hedgehog 3 (ソニック・ザ・ヘッジホッグ3 Sonikku za Hejjihoggu 3) (Sonic 3 in PAL and Australia regions) is a platform game and the 4th installment in the Sonic the Hedgehog series for the Sega Mega Drive/Genesis. It was developed in the United States by members of Sonic Team working at SEGA Technical Institute, and was published by SEGA, debuting worldwide in the first half of 1994. The game is a sequel to Sonic the Hedgehog 2 and follows on directly from the end of the last game, in which Sonic defeated his enemy, Dr. Robotnik. Crash-landing on a floating island, Sonic encounters a new character, Knuckles the Echidna, and must once more retrieve the Chaos Emeralds while also working to stop Dr. Robotnik from relaunching his ship, the Death Egg.

In the Super Smash Flash series

Knuckles the Echidna makes his debut appearance in this game. Knuckles would become a playable character in Super Smash Flash, and his ability to attack while jumping originates from this game as well.

Originally in Super Smash Flash 2, Sonic's down special move in the air was the Bounce Attack, which made its debut in this game. This was removed in Beta.