Sonic the Hedgehog is the titular character and primary protagonist of the Sonic the Hedgehog video game series published by Sega, as well as numerous spin-off comics, animations and other sources of media. Sonic is a blue anthropomorphic hedgehog who can run at supersonic speeds and curl into a ball, primarily to attack enemies. In most games, Sonic must race through levels, collecting power-up rings and avoiding obstacles and enemies.

Programmer Yuji Naka and artist Naoto Ohshima are generally credited with creating Sonic. Most of the games are developed by Sonic Team. The original Sonic the Hedgehog (1991) was released to provide Sega with a mascot to rival Nintendo's flagship character Mario. Sonic was redesigned by Yuji Uekawa for Sonic Adventure (1998), with a more mature look designed to appeal to older players.

Sonic is one of the world's best-known video game characters and a gaming icon. His series had sold more than 80 million copies by 2011. In 2005, Sonic was one of the first game character inductees into the Walk of Game alongside Mario, Link, and Master Chief.

"What you see is what you get! Just a guy that loves adventure! I'm Sonic the Hedgehog!"