Sonic the Hedgehog 4 (codenamed Project Needlemouse) is a 2010 episodic platform video game in development as part of the Sonic the Hedgehog series for the PlayStation 3, Xbox 360 and the Wii. It is targeted for release in 2010.

The game is a direct sequel to Sonic the Hedgehog 3 and Sonic & Knuckles and will be playable in high definition on the PlayStation 3 and Xbox 360. The Wii and PlayStation 3 version of the game will feature support for motion controls. The game returns to the roots of the Sonic series, and is strictly a 2D side-scrolling game rendered using 3D models; Sonic the Hedgehog will be the only playable character in the game.