Football hooliganism, also known as football rioting, constitutes violence and other destructive behaviors perpetrated by spectators at association football events. Football hooliganism typically involves conflict between pseudo-tribes, formed to intimidate and attack supporters of other teams. Certain clubs have long-standing rivalries with other clubs and hooliganism associated with matches between them (sometimes called local derbies) can be more severe. Conflict may arise at any point, before, during or after matches and occasionally outside of game situations. Participants often select locations away from stadiums to avoid arrest by the police, but conflict can also erupt spontaneously inside the stadium or in the surrounding streets. In extreme cases, hooligans, police and bystanders have been killed, and riot police have intervened. Hooligan-led violence has been called "aggro" (short for "aggression") and "bovver" (the Cockney pronunciation of "bother", i.e. trouble).

Hooligans who have the time and money may follow national teams to away matches and engage in hooligan behaviour against the hooligans of the home team. They may also become involved in disorder involving the general public. While national-level firms do not exist in the form of club-level firms, hooligans supporting the national team may use a collective name indicating their allegiance.^{[citation needed]}

Hooliganism can create a high level of violence at football matches. Outside of the physical violence, the behavior of these fans is extremely disorderly and leads to conflict breaking out. In some cases, hooliganism involves extreme ideological pathways such as Neo-Nazism or white supremacism. These extreme beliefs which they take on can further invigorate the violence. Hooligans intentions are usually not focused on the match itself, despite club rivalries or pride often justifying the violence. They engage in behavior that risks them being arrested before the match, denied admittance to the stadium, ejected from the stadium during the match or banned from attending future matches. Hooligan groups often associate themselves with, and congregate in, a specific section (called an end in England) of their team's stadium, and sometimes they include the section's name in the name of their group.

In other parts of Europe and the world these groups are known as Ultras, in Hispanic America as Barra Bravas and Brazil as Torcidas Organizadas. However, it is important to not mix up hooligans with these as they do not necessarily depict violence in the same manner as hooliganism. These are supporters' groups with the primary objective of fanatically supporting the club through chants, flags, displays and organizing trips to away games. Due to their fanaticism, many of those groups frequently become embroiled with hooliganism, but do not have the explicit objective of causing violence.

The type of violence committed by hooligans can come in a number of forms: starting fires, unarmed and armed fighting, hateful speech, and occasionally even violent acts committed against the players such as throwing bottles or bananas to physically harm or racially attack players.

In 2014 in a match between Barcelona and Villareal, a fan racially abused Dani Alves, the Barcelona right back, throwing a banana at him, insinuating he was a monkey, a known racial stereotype against black people.

Violence can also come as a result of a player's poor performance. Fans and in particular hooligans hold their mistakes to them, ridiculing them in any way possible. Andres Escobar was a Colombian defender whose own goal error led to the elimination of Colombia in the 1994 World Cup, resulting in him being subsequently murdered.

A study from the university of Munich analyzed violent crime in Germany from 2011 to 2015 and how much of that can be attributed to football. It found that on the day of the game, violent crime increased by 17% and during major rivalry games, violent crimes increased by 63%.