Sonic the Hedgehog 4 refers to two episodes of a video game saga starring Sonic the Hedgehog:
- Sonic the Hedgehog 4: Episode I, an episode of a high-definition 2D Sonic the Hedgehog game released in 2010 and described as a return of Sonic the Hedgehog "back to his 2D roots"
- Sonic the Hedgehog 4: Episode II, the second installment of this game, released in 2012.
Before Sega released the Sonic the Hedgehog 4 games, various other games were thought of as successors to Sonic the Hedgehog 3:
- Sonic & Knuckles, the fourth main Sonic game on the Mega Drive/Sega Genesis, though it is considered and was developed as part of Sonic 3
- Sonic 3D, the next home console game after Sonic & Knuckles to star Sonic
- Sonic Adventure, the next home console game in the main series after Sonic & Knuckles
- Sonic the Hedgehog: Triple Trouble, the fourth Sonic game on the Sega Game Gear
- Sonic Crackers, a prototype Sonic game on Sega Megadrive that later became Knuckles Chaotix on the 32X, often labelled as "SONIC 4" when its circulated on emulator websites
- A pirated Speedy Gonzales game for the Super Nintendo that was modified to include Sonic in place of Speedy and Mario in place of the captives