A riot is a form of civil disorder characterized often by what is thought of as disorganized groups lashing out in a sudden and intense rash of violence against authority, property or people. While individuals may attempt to lead or control a riot, riots are thought to be typically chaotic and exhibit herd behaviour, and usually generated by civil unrest. However, there is a growing body of evidence to suggest that riots are not irrational, herd-like behaviour, but follow inverted social norms.

Riot may refer to a number of different topics, including:

• Riot, a form of civil disorder
• Riot (band), a American heavy metal band
• Riot (song), a song by Three Days Grace
• Riot!, the title of the second album by Paramore
• Riot (comics), a fictional character
• Riot, a manga by Satoshi Shiki
• The Riot, a 1913 film starring Fatty Arbuckle
• Riot (film), a 1969 film starring Jim Brown and Gene Hackman
• Riot (1997 film), a 1997 made-for-television movie starring Luke Perry, Mario Van Peebles, and Lucy Liu
• RiOT, a Japanese video game developer
• MOS Technology 6532 RAM-I/O-Timer (RIOT), an integrated circuit
• Royal Institute of Technology, a university in Sweden
• Riot Games, an independent game developer known for League of Legends
• Ra Ra Riot, an American indie rock band from Syracuse, New York