Guitar Hero is a 2005 music rhythm video game developed by Harmonix and published by RedOctane for the PlayStation 2. It is the first entry in the Guitar Hero series. Guitar Hero was released in November 2005 in North America, April 2006 in Europe and June 2006 in Australia. The game's development was a result of collaboration between RedOctane and Harmonix to bring a Guitar Freaks-like game to United States.

The game features a guitar-shaped controller (resembling a miniature Gibson SG) that the player uses to simulate playing rock music. The gameplay is similar to GuitarFreaks, in that the player presses buttons on the guitar controller in time with musical notes that scroll on the game screen. The game features covers of 30 popular rock songs spanning five decades of rock, from the 1960s up through 2005, in addition to bonus tracks. Guitar Hero became a surprise hit, earning critical acclaim and winning many awards from major video game publications, and was considered one of the most influential games of the first decade of the 21st century. The game's success launched the Guitar Hero franchise, which has earned more than $2 billion in sales, spawning several sequels, expansions, and other game-related products.