Guitar Hero is a series of music video games first published in 2005 by RedOctane and distributed by Activision in which players use a guitar-shaped peripheral to simulate the playing of lead and bass guitar across numerous rock music songs. Players match notes that scroll on-screen to colored fret buttons on the controller, strumming the controller in time to the music in order to score points and keep the virtual audience excited. The games attempt to mimic many features of playing a real guitar, including the use of fast-fingering hammer-ons and pull-offs and the use of the whammy bar to alter the pitch of notes.

With the introduction of Guitar Hero World Tour in 2008, the game includes support for a four-player band including vocals and drums.

The game currently has four major releases and three expansions on gaming consoles, and with spinoffs for Windows and Macintosh systems, mobile phones, the Nintendo DS, and an arcade game, with several more titles announced for future release. The Guitar Hero franchise has become a cultural phenomenon and learning and development tool for medical purposes, and has revolutionized the modern music industry. The series has sold 24 million units, earning US$1.6 billion at retail; The third game in the series, Guitar Hero III: Legends of Rock is the first single video game to exceed $1 billion in total sales.